- 제출된 URL:
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- 보고서 완료:
링크 · 12개 결과
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| 링크 | 텍스트 |
|---|---|
| https://github.com/ztlpn/minilp | minilp |
| https://github.com/Specy/rooc/blob/main/src/solvers/milp_solver.rs#L66 | adding an adapter |
| https://github.com/mtolmacs/wasm2map | wasm2map |
| https://github.com/ztlpn/minilp/issues/6 | One random issue |
| https://github.com/ztlpn/minilp/blob/master/src/helpers.rs#L26 | unsafe |
| https://github.com/sparsemat/sprs/issues/370#issuecomment-2446583795 | an issue |
| https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=0b00575c9057e816cddce89d00a0d856 | minimal reproduction |
| https://github.com/rust-lang/rust/issues/132353 | bug report |
| https://github.com/specy/rooc | rooc library |
| https://github.com/Specy/microlp | minilp |
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| 이름 | 유형 |
|---|---|
| 0 | object |
| 1 | object |
| onbeforetoggle | object |
| documentPictureInPicture | object |
| onscrollend | object |
| google_js_reporting_queue | object |
| google_srt | number |
| google_logging_queue | object |
| google_ad_modifications | object |
| ggeac | object |
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"><div class="column" style="flex: 1; position: relative;"><div class="background svelte-te071l"><canvas class="background-image svelte-te071l" width="68" height="51"></canvas></div> <div class="column" style="flex: 1; z-index: 2"><nav class="nav svelte-1mg1ajw"><div class="desktop-menu svelte-1mg1ajw"><a class="logo-wrapper svelte-1awiheq" href="/"><img src="/images/logo.png" alt="logo" class="logo svelte-1awiheq"> <div class="name svelte-1awiheq"><div>Specy</div> <div class="overflow-wrapper svelte-1awiheq"><div class="logo-line-wrapper svelte-1awiheq"><div class="logo-line svelte-1awiheq "></div> <div class="logo-app svelte-1awiheq"><span class="svelte-1awiheq">.</span> app</div></div></div></div></a><!----> <div class="links svelte-1mg1ajw" style=""><a href="/" style="" class="svelte-1mg1ajw">Home</a> <a href="/#web-apps" class="svelte-1mg1ajw">Apps</a> <a href="/blog" style="color: var(--accent)" class="svelte-1mg1ajw">Blog</a> <a href="/donate" style="" class="svelte-1mg1ajw">Donate</a></div></div> <div class="mobile-menu svelte-1mg1ajw "><div class="mobile-row svelte-1mg1ajw"><a class="logo-wrapper svelte-1awiheq" href="/"><img src="/images/logo.png" alt="logo" class="logo svelte-1awiheq"> <div class="name svelte-1awiheq"><div>Specy</div> <div class="overflow-wrapper svelte-1awiheq"><div class="logo-line-wrapper svelte-1awiheq"><div class="logo-line svelte-1awiheq "></div> <div class="logo-app svelte-1awiheq"><span class="svelte-1awiheq">.</span> app</div></div></div></div></a><!----> <div class="top-mobile-menu svelte-1mg1ajw"><div style="height:2rem"><!--[!--><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="svelte-c8tyih"><!--[!--><!--]--><!----><path d="M3 18h18v-2H3v2zm0-5h18v-2H3v2zm0-7v2h18V6H3z"></path><!----></svg><!--]--></div></div></div> <div class="links-mobile svelte-1mg1ajw "><a href="/" style="" class="svelte-1mg1ajw">Home</a> <a href="/#web-apps" style="" class="svelte-1mg1ajw">Apps</a> <a href="/blog" style="color: var(--accent)" class="svelte-1mg1ajw">Blog</a> <a href="/donate" style="" class="svelte-1mg1ajw">Donate</a></div></div></nav><!----> <!----><div class="progress svelte-1ak3fvo"></div> <div class="page column svelte-1ak3fvo"><!----><!----><article class="content-wrapper svelte-jyj42k"><div class="content svelte-jyj42k"><header style="display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 1rem"><h1 class="main-header svelte-jyj42k">A rustc soundness bug in the wild</h1> <p class="date-published svelte-jyj42k">11/13/2024</p></header> <section class="blog-description svelte-jyj42k">How a bug in the rustc compiler drove me to madness for two days</section> <div class="badge-wrapper svelte-jyj42k"><!--[--><span class="badge svelte-jyj42k" style="--index: 0">rust</span><span class="badge svelte-jyj42k" style="--index: 1">rooc</span><!--]--></div> <!--[--><h1>Related Projects</h1> <div class="projects-wrapper svelte-jyj42k"><!--[--><div class="project svelte-1g7bjn8"><div class="row svelte-1g7bjn8"><img src="/images/rooc.png" alt="Rooc" class="svelte-1g7bjn8"> <div class="app-title svelte-1g7bjn8">Rooc</div></div> <div class="description svelte-1g7bjn8">Modeling language to solve MILP problems in the browser</div> <a href="https://rooc.specy.app" target="_blank" class="open-btn svelte-1g7bjn8" style="background-color: rgb(83, 87, 165)" rel="canonical"><div class="svelte-1g7bjn8">Open</div> <div class="icon svelte-1g7bjn8"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="svelte-c8tyih"><!--[!--><!--]--><!----><path d="M19 19H5V5h7V3H5c-1.11 0-2 .9-2 2v14c0 1.1.89 2 2 2h14c1.1 0 2-.9 2-2v-7h-2v7zM14 3v2h3.59l-9.83 9.83 1.41 1.41L19 6.41V10h2V3h-7z"></path><!----></svg><!----></div></a></div><!--]--></div><!--]--> <section class="md-content svelte-jyj42k"><h1 id="how-it-started"><a href="#how-it-started">How it started</a></h1> <p>I was working on <a href="https://rooc.specy.app" rel="nofollow">rooc</a>, a modeling language for optimization problems running in the web;
After months of “just one more feature” i decided to stop adding new things to the language, and instead focus on improving the
solvers, which so far implemented only a very simple one which i developed.</p> <p>My goal was to be able to run everything in the browser, so solvers must be able to compile to WebAssembly.</p> <p>The easiest way to do this is to find pure rust libraries, which would allow me to simply compile the rust code to the wasm target.</p> <p>After many failed attempts at compiling for wasm, searching through the whole crates.io, i stumbled upon <a href="https://github.com/ztlpn/minilp" rel="nofollow">minilp</a>, a rust only linear programming library. Perfect!</p> <p>But wait… <em>“The project was archived 2 years ago, last commit 4 years ago”</em>, oh well, i heard that rust is a stable language, so it should be fine, right?</p> <div class="container svelte-5crb98" style="font-size: 1.3rem; margin: -1rem 0"><div class="wavy-text svelte-5crb98"><!--[--><span style="
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" class="svelte-5crb98">?</span><!--]--></div></div><!----> <h1 id="implementation"><a href="#implementation">Implementation</a></h1> <p>After discovering the library i immediately added it as a solver to rooc, which was as easy as <a href="https://github.com/Specy/rooc/blob/main/src/solvers/milp_solver.rs#L66" rel="nofollow">adding an adapter</a> that transformed a <code>LinearModel</code> into a <code>minilp::Problem</code>.</p> <p>Let’s see how that goes!</p> <blockquote><p><code>cargo test</code></p></blockquote> <pre class="language-undefined"><!----><code class="language-undefined">Running testssolver_tests.rs
running 18 tests
...
test result: ok. 18 passed; 0 failed; 0 measured; 0 filtered out; finished in 0.03s</code><!----></pre> <p>Looks good to me! Let’s publish a new version of the library to npm with this newly added solver!</p> <p>But wait, right, before that i should probably test it in the browser, <em>just to make sure</em>.</p> <pre class="language-undefined"><!----><code class="language-undefined">Uncaught (in promise) RuntimeError: unreachable
at __rust_start_panic (http://127.0.0.1:8080/wasm_bg.wasm:wasm-function[346]:0x274ec)
at rust_panic (http://127.0.0.1:8080/wasm_bg.wasm:wasm-function[254]:0x26d0b)
...</code><!----></pre> <p>Huh? A panic? Oh well, i guess even this library does not work on the web…</p> <p>Being a bit discouraged, i kept searching on crates.io for alternatives, but sadly found none.</p> <p>My only chance was getting minilp to work, it seemed like there were no weird dependencies, no usage of OS specific things, so it <em>should</em> have worked on the web.</p> <h1 id="debugging-begins"><a href="#debugging-begins">Debugging begins</a></h1> <p>Maybe it’s a web only problem? WASM stack traces are a bit… cryptic, you don’t really know where or what happened, as it completely strips away any kind of debug information to keep bundle sizes small.
But let’s try using <a href="https://github.com/mtolmacs/wasm2map" rel="nofollow">wasm2map</a> to add debug map information to the wasm file, and see if we can get a better stack trace.</p> <pre class="language-undefined"><!----><code class="language-undefined">called `Option::unwrap()` on a `None` value
stack backtrace:
...
3: core::option::unwrap_failed
4: microlp::order_simple
5: microlp::main</code><!----></pre> <p>Ah ok, it’s just a simple unwrap on a None value, i probably messed up somewhere in the adapter code.
Let me create a new test using the same model that had issues, so i don’t have a regression in the future.</p> <blockquote><p><code>cargo test</code></p></blockquote> <pre class="language-undefined"><!----><code class="language-undefined">Running testssolver_tests.rs
running 19 tests
...
test result: ok. 19 passed; 0 failed; 0 measured; 0 filtered out; finished in 0.03s</code><!----></pre> <p>What??? The test passed?</p> <div class="container svelte-5crb98" style="font-size: 1.3rem; margin: -1rem 0"><div class="wavy-text svelte-5crb98"><!--[--><span style="
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" class="svelte-5crb98">?</span><!--]--></div></div><!----> <p>I just had this panic on me a <em>few seconds ago</em>?</p> <p>Ah whatever, let’s go to the issues page of the minilp repository, maybe someone else had this issue before.</p> <p><a href="https://github.com/ztlpn/minilp/issues/6" rel="nofollow">One random issue</a> shows another panic at runtime, so i guess the library doesn’t guarantee the lack of panics,
and it being archived, i should probably just fork it and fix it myself.</p> <p>Let’s look at the <code>minilp::order_simple</code> function and see what’s going on there.</p> <pre class="language-rust"><!----><code class="language-rust"><span class="token keyword">pub</span> <span class="token keyword">fn</span> <span class="token function-definition function">order_simple</span><span class="token operator"><</span><span class="token lifetime-annotation symbol">'a</span><span class="token operator">></span><span class="token punctuation">(</span>size<span class="token punctuation">:</span> <span class="token keyword">usize</span><span class="token punctuation">,</span> get_col<span class="token punctuation">:</span> <span class="token keyword">impl</span> <span class="token class-name">Fn</span><span class="token punctuation">(</span><span class="token keyword">usize</span><span class="token punctuation">)</span> <span class="token punctuation">-></span> <span class="token operator">&</span><span class="token lifetime-annotation symbol">'a</span> <span class="token punctuation">[</span><span class="token keyword">usize</span><span class="token punctuation">]</span><span class="token punctuation">)</span> <span class="token punctuation">-></span> <span class="token class-name">Perm</span> <span class="token punctuation">{</span>
<span class="token keyword">let</span> <span class="token keyword">mut</span> cols_queue <span class="token operator">=</span> <span class="token class-name">ColsQueue</span><span class="token punctuation">::</span><span class="token function">new</span><span class="token punctuation">(</span>size<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token comment">//some code...</span>
<span class="token keyword">let</span> <span class="token keyword">mut</span> new2orig <span class="token operator">=</span> <span class="token class-name">Vec</span><span class="token punctuation">::</span><span class="token function">with_capacity</span><span class="token punctuation">(</span>size<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">while</span> new2orig<span class="token punctuation">.</span><span class="token function">len</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator"><</span> size <span class="token punctuation">{</span>
<span class="token keyword">let</span> min <span class="token operator">=</span> cols_queue<span class="token punctuation">.</span><span class="token function">min</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token macro property">println!</span><span class="token punctuation">(</span><span class="token string">"min {:?}"</span><span class="token punctuation">,</span> min<span class="token punctuation">)</span><span class="token punctuation">;</span>
new2orig<span class="token punctuation">.</span><span class="token function">push</span><span class="token punctuation">(</span>min<span class="token punctuation">.</span><span class="token function">unwrap</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token comment">//other code...</span>
<span class="token punctuation">}</span></code><!----></pre> <p>It seems correct? <code>cols_queue</code> is initialized with <code>size</code> so it should never be out of elements to pop, is there something else
that is modifying the <code>cols_queue</code>?</p> <p>I put a breakpoint in the <code>while</code> loop to see what’s going on, and… <em>it did not panic</em>?</p> <p>Ok this is starting to get weird, let’s look more in depth at the <code>fn pop_min(&mut self) -> Option<usize></code> function,
it is returning a <code>None</code> value, so let’s put some debug prints to see:</p> <pre class="language-rust"><!----><code class="language-rust"><span class="token keyword">fn</span> <span class="token function-definition function">pop_min</span><span class="token punctuation">(</span><span class="token operator">&</span><span class="token keyword">mut</span> <span class="token keyword">self</span><span class="token punctuation">)</span> <span class="token punctuation">-></span> <span class="token class-name">Option</span><span class="token operator"><</span><span class="token keyword">usize</span><span class="token operator">></span> <span class="token punctuation">{</span>
<span class="token keyword">let</span> col <span class="token operator">=</span> <span class="token keyword">loop</span> <span class="token punctuation">{</span>
<span class="token keyword">if</span> <span class="token keyword">self</span><span class="token punctuation">.</span>min_score <span class="token operator">>=</span> <span class="token keyword">self</span><span class="token punctuation">.</span>score2head<span class="token punctuation">.</span><span class="token function">len</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token macro property">println!</span><span class="token punctuation">(</span><span class="token string">"None on min_score: {}"</span><span class="token punctuation">,</span> <span class="token keyword">self</span><span class="token punctuation">.</span>min_score<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">return</span> <span class="token class-name">None</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">if</span> <span class="token keyword">let</span> <span class="token class-name">Some</span><span class="token punctuation">(</span>col<span class="token punctuation">)</span> <span class="token operator">=</span> <span class="token keyword">self</span><span class="token punctuation">.</span>score2head<span class="token punctuation">[</span><span class="token keyword">self</span><span class="token punctuation">.</span>min_score<span class="token punctuation">]</span> <span class="token punctuation">{</span>
<span class="token keyword">break</span> col<span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">self</span><span class="token punctuation">.</span>min_score <span class="token operator">+=</span> <span class="token number">1</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">self</span><span class="token punctuation">.</span><span class="token function">remove</span><span class="token punctuation">(</span>col<span class="token punctuation">,</span> <span class="token keyword">self</span><span class="token punctuation">.</span>min_score<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token class-name">Some</span><span class="token punctuation">(</span>col<span class="token punctuation">)</span>
<span class="token punctuation">}</span></code><!----></pre> <blockquote><p><code>cargo run</code></p></blockquote> <pre class="language-bash"><!----><code class="language-bash">min: Some<span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span>
min: Some<span class="token punctuation">(</span><span class="token number">2</span><span class="token punctuation">)</span>
min: Some<span class="token punctuation">(</span><span class="token number">3</span><span class="token punctuation">)</span>
called <span class="token variable"><span class="token variable">`</span>Option::unwrap<span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token variable">`</span></span> on a <span class="token variable"><span class="token variable">`</span>None<span class="token variable">`</span></span> value</code><!----></pre> <p>Ok good, at least the bug happens now? <em>I guess?</em> But where is the <code>None on min_score: {}</code> print that i put in the <em>only</em> place where <code>None</code> is returned?</p> <p>Let’s add more prints!</p> <video src="https://github.com/user-attachments/assets/2631f7bf-4363-4305-8950-03b94b018d61" style="width: 100%; border-radius: 0.5rem" controls=""></video> <p><em>Yeeeeeeah</em>, no, this cannot be sound, there must be something wrong somewhere, i did see an <a href="https://github.com/ztlpn/minilp/blob/master/src/helpers.rs#L26" rel="nofollow">unsafe</a> in the library, so maybe some memory corruption is happening?</p> <p>Running miri did not show any issues, but going step by step with my debugger did show an illegal memory access, so definitely something is wrong with the library.</p> <p>I also noticed that the bug happens <em>only</em> when running in release mode, so that does narrow down the issue a bit.</p> <p>Just to be sure i ran the same code in debug mode but disabling all debug checks like bound checking and overflow checking, but the bug
did not reproduce. I managed to narrow it down to <code>opt-level = 1</code> causing the panic.</p> <p>I try to remove all <code>unsafe</code> usage everywhere in the library to make sure that’s not the issue. But the panic is still there.</p> <p>Hm, the only dependency of the crate is <code>sprs</code> which has <em>a ton</em> of unsafe code, let’s file <a href="https://github.com/sparsemat/sprs/issues/370#issuecomment-2446583795" rel="nofollow">an issue</a> to see if i’m breaking some invariants.</p> <blockquote><p>It is not clear it is a bug in sprs, try the following:</p> <pre class="language-rust"><!----><code class="language-rust"><span class="token function">order_simple</span><span class="token punctuation">(</span><span class="token number">4</span><span class="token punctuation">,</span> <span class="token closure-params"><span class="token closure-punctuation punctuation">|</span>c<span class="token closure-punctuation punctuation">|</span></span> <span class="token punctuation">{</span>
<span class="token keyword">match</span> c <span class="token punctuation">{</span>
<span class="token number">0</span> <span class="token operator">=></span> <span class="token operator">&</span><span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">]</span><span class="token punctuation">,</span>
<span class="token number">1</span> <span class="token operator">=></span> <span class="token operator">&</span><span class="token punctuation">[</span><span class="token number">2</span><span class="token punctuation">]</span><span class="token punctuation">,</span>
<span class="token number">2</span> <span class="token operator">=></span> <span class="token operator">&</span><span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">1</span><span class="token punctuation">]</span><span class="token punctuation">,</span>
<span class="token number">3</span> <span class="token operator">=></span> <span class="token operator">&</span><span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">]</span><span class="token punctuation">,</span>
_ <span class="token operator">=></span> <span class="token macro property">unreachable!</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span>
<span class="token punctuation">}</span>
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span></code><!----></pre></blockquote> <p>Which… still panics? <em>Ok, ok, ok</em>, let’s recap:</p> <ul><li>The bug happens only in release mode</li> <li>There is no unsafe code anywhere in the library</li> <li>Miri does not report any issues</li> <li>There are no dependencies which might cause issues</li> <li>There is only 100% plain safe rust code</li></ul> <p>So how can it be panicking? Isn’t the whole purpose of rust to not have this kind of issues if you are not using unsafe code?</p> <h1 id="the-bug-report"><a href="#the-bug-report">The bug report</a></h1> <p>I decided to make sure i wasn’t making any silly mistakes and tried to build a <a href="https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=0b00575c9057e816cddce89d00a0d856" rel="nofollow">minimal reproduction</a> using no dependencies or unsafe code:</p> <pre class="language-rust"><!----><code class="language-rust"><span class="token keyword">fn</span> <span class="token function-definition function">main</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token function">order_simple</span><span class="token punctuation">(</span><span class="token number">4</span><span class="token punctuation">,</span> <span class="token closure-params"><span class="token closure-punctuation punctuation">|</span>c<span class="token closure-punctuation punctuation">|</span></span> <span class="token punctuation">{</span>
<span class="token keyword">match</span> c <span class="token punctuation">{</span>
<span class="token number">0</span> <span class="token operator">=></span> <span class="token operator">&</span><span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">]</span><span class="token punctuation">,</span>
<span class="token number">1</span> <span class="token operator">=></span> <span class="token operator">&</span><span class="token punctuation">[</span><span class="token number">2</span><span class="token punctuation">]</span><span class="token punctuation">,</span>
<span class="token number">2</span> <span class="token operator">=></span> <span class="token operator">&</span><span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">1</span><span class="token punctuation">]</span><span class="token punctuation">,</span>
<span class="token number">3</span> <span class="token operator">=></span> <span class="token operator">&</span><span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">]</span><span class="token punctuation">,</span>
_ <span class="token operator">=></span> <span class="token macro property">unreachable!</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span>
<span class="token punctuation">}</span>
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token macro property">println!</span><span class="token punctuation">(</span><span class="token string">"All ok! Try running in release mode"</span><span class="token punctuation">)</span>
<span class="token punctuation">}</span></code><!----></pre> <blockquote><p><code>cargo run</code></p></blockquote> <pre class="language-undefined"><!----><code class="language-undefined">All ok! Try running in release mode</code><!----></pre> <blockquote><p><code>cargo run --release</code></p></blockquote> <pre class="language-bash"><!----><code class="language-bash">thread <span class="token string">'main'</span> panicked at <span class="token string">'called `Option::unwrap()` on a `None` value'</span></code><!----></pre> <p>Yup. Checks out. Time to file a <a href="https://github.com/rust-lang/rust/issues/132353" rel="nofollow">bug report</a> to the rustc repository!</p> <h1 id="the-fix"><a href="#the-fix">The fix</a></h1> <p>After a few minutes the bug was minimized to just:</p> <pre class="language-rust"><!----><code class="language-rust"><span class="token keyword">fn</span> <span class="token function-definition function">pop_min</span><span class="token punctuation">(</span><span class="token keyword">mut</span> score2head<span class="token punctuation">:</span> <span class="token class-name">Vec</span><span class="token operator"><</span><span class="token class-name">Option</span><span class="token operator"><</span><span class="token keyword">usize</span><span class="token operator">>></span><span class="token punctuation">)</span> <span class="token punctuation">-></span> <span class="token class-name">Option</span><span class="token operator"><</span><span class="token keyword">usize</span><span class="token operator">></span> <span class="token punctuation">{</span>
<span class="token keyword">loop</span> <span class="token punctuation">{</span>
<span class="token keyword">if</span> <span class="token keyword">let</span> <span class="token class-name">Some</span><span class="token punctuation">(</span>col<span class="token punctuation">)</span> <span class="token operator">=</span> score2head<span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">]</span> <span class="token punctuation">{</span>
score2head<span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token class-name">None</span><span class="token punctuation">;</span>
<span class="token keyword">return</span> <span class="token class-name">Some</span><span class="token punctuation">(</span>col<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token punctuation">}</span>
<span class="token punctuation">}</span></code><!----></pre> <p>which turns out to have been caused by a <code>unsound_mir_opts</code> in the rustc compiler.
The issue was given a <code>P-critical</code> priority, the bugged code fixed in a few days, and released a week later.</p> <h1 id="conclusion"><a href="#conclusion">Conclusion</a></h1> <p>After the bug was resolved i managed to publish the new version of the <a href="https://github.com/specy/rooc" rel="nofollow">rooc library</a> which <em>now does</em> work in the browser, also forked the <a href="https://github.com/Specy/microlp" rel="nofollow">minilp</a> crate to fix some bugs and add some new features.</p> <p>I’m by no means a rust expert, nor a good low-level programmer, i’m just a frontender after all! But this experience taught
me a ton about debugging so i wanted to share the thought process going through this bug.</p><!----></section></div></article><!----><!----><!----><!----></div><!----> <div class="content-under svelte-1ak3fvo"></div><!----><!----></div></div><!----> <footer class="footer svelte-i1g2nx"><div class="footer-inner svelte-i1g2nx"><div class="footer-justify svelte-i1g2nx"><div class="logo-mobile svelte-i1g2nx"><a class="logo-wrapper svelte-i1g2nx" href="https://portfolio.specy.app" target="_blank"><img src="/images/logo.png" alt="logo" class="logo svelte-i1g2nx"> <div class="svelte-i1g2nx">Portfolio</div></a></div> <div class="logo-desktop svelte-i1g2nx"><div class="logo-wrapper svelte-i1g2nx"><img src="/images/logo.png" alt="logo" class="logo svelte-i1g2nx"> <div class="logo-text svelte-i1g2nx">Specy</div></div></div> <div class="desktop-portfolio svelte-i1g2nx"><a href="https://portfolio.specy.app" target="_blank" class="svelte-i1g2nx">Portfolio</a></div> <div class="icon-wrapper svelte-i1g2nx"><a class="icon svelte-i1g2nx" href="https://github.com/Specy" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 496 512" class="svelte-c8tyih"><!--[!--><!--]--><!----><path d="M165.9 397.4c0 2-2.3 3.6-5.2 3.6-3.3.3-5.6-1.3-5.6-3.6 0-2 2.3-3.6 5.2-3.6 3-.3 5.6 1.3 5.6 3.6zm-31.1-4.5c-.7 2 1.3 4.3 4.3 4.9 2.6 1 5.6 0 6.2-2s-1.3-4.3-4.3-5.2c-2.6-.7-5.5.3-6.2 2.3zm44.2-1.7c-2.9.7-4.9 2.6-4.6 4.9.3 2 2.9 3.3 5.9 2.6 2.9-.7 4.9-2.6 4.6-4.6-.3-1.9-3-3.2-5.9-2.9zM244.8 8C106.1 8 0 113.3 0 252c0 110.9 69.8 205.8 169.5 239.2 12.8 2.3 17.3-5.6 17.3-12.1 0-6.2-.3-40.4-.3-61.4 0 0-70 15-84.7-29.8 0 0-11.4-29.1-27.8-36.6 0 0-22.9-15.7 1.6-15.4 0 0 24.9 2 38.6 25.8 21.9 38.6 58.6 27.5 72.9 20.9 2.3-16 8.8-27.1 16-33.7-55.9-6.2-112.3-14.3-112.3-110.5 0-27.5 7.6-41.3 23.6-58.9-2.6-6.5-11.1-33.3 2.6-67.9 20.9-6.5 69 27 69 27 20-5.6 41.5-8.5 62.8-8.5s42.8 2.9 62.8 8.5c0 0 48.1-33.6 69-27 13.7 34.7 5.2 61.4 2.6 67.9 16 17.7 25.8 31.5 25.8 58.9 0 96.5-58.9 104.2-114.8 110.5 9.2 7.9 17 22.9 17 46.4 0 33.7-.3 75.4-.3 83.6 0 6.5 4.6 14.4 17.3 12.1C428.2 457.8 496 362.9 496 252 496 113.3 383.5 8 244.8 8zM97.2 352.9c-1.3 1-1 3.3.7 5.2 1.6 1.6 3.9 2.3 5.2 1 1.3-1 1-3.3-.7-5.2-1.6-1.6-3.9-2.3-5.2-1zm-10.8-8.1c-.7 1.3.3 2.9 2.3 3.9 1.6 1 3.6.7 4.3-.7.7-1.3-.3-2.9-2.3-3.9-2-.6-3.6-.3-4.3.7zm32.4 35.6c-1.6 1.3-1 4.3 1.3 6.2 2.3 2.3 5.2 2.6 6.5 1 1.3-1.3.7-4.3-1.3-6.2-2.2-2.3-5.2-2.6-6.5-1zm-11.4-14.7c-1.6 1-1.6 3.6 0 5.9 1.6 2.3 4.3 3.3 5.6 2.3 1.6-1.3 1.6-3.9 0-6.2-1.4-2.3-4-3.3-5.6-2z"></path><!----></svg><!----></a> <a class="icon svelte-i1g2nx" href="https://discord.gg/Arsf65YYHq" target="_blank" style="margin-top: 0.2rem;"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512" class="svelte-c8tyih"><!--[!--><!--]--><!----><path d="M297.216 243.2c0 15.616-11.52 28.416-26.112 28.416-14.336 0-26.112-12.8-26.112-28.416s11.52-28.416 26.112-28.416c14.592 0 26.112 12.8 26.112 28.416zm-119.552-28.416c-14.592 0-26.112 12.8-26.112 28.416s11.776 28.416 26.112 28.416c14.592 0 26.112-12.8 26.112-28.416.256-15.616-11.52-28.416-26.112-28.416zM448 52.736V512c-64.494-56.994-43.868-38.128-118.784-107.776l13.568 47.36H52.48C23.552 451.584 0 428.032 0 398.848V52.736C0 23.552 23.552 0 52.48 0h343.04C424.448 0 448 23.552 448 52.736zm-72.96 242.688c0-82.432-36.864-149.248-36.864-149.248-36.864-27.648-71.936-26.88-71.936-26.88l-3.584 4.096c43.52 13.312 63.744 32.512 63.744 32.512-60.811-33.329-132.244-33.335-191.232-7.424-9.472 4.352-15.104 7.424-15.104 7.424s21.248-20.224 67.328-33.536l-2.56-3.072s-35.072-.768-71.936 26.88c0 0-36.864 66.816-36.864 149.248 0 0 21.504 37.12 78.08 38.912 0 0 9.472-11.52 17.152-21.248-32.512-9.728-44.8-30.208-44.8-30.208 3.766 2.636 9.976 6.053 10.496 6.4 43.21 24.198 104.588 32.126 159.744 8.96 8.96-3.328 18.944-8.192 29.44-15.104 0 0-12.8 20.992-46.336 30.464 7.68 9.728 16.896 20.736 16.896 20.736 56.576-1.792 78.336-38.912 78.336-38.912z"></path><!----></svg><!----></a></div></div> <div class="copyright svelte-i1g2nx">© 2024 Specy. All rights reserved.</div></div></footer><!----><!----> <!----><div class="toast-wrapper svelte-1lj56nd "><div class="toast-title svelte-1lj56nd" style="border-color:"><div></div> <div class="icon svelte-wuqdah" style="width:1.2rem; min-width: 1.2; height:1.2rem; ;"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 352 512" class="svelte-c8tyih"><!--[!--><!--]--><!----><path d="M242.72 256l100.07-100.07c12.28-12.28 12.28-32.19 0-44.48l-22.24-22.24c-12.28-12.28-32.19-12.28-44.48 0L176 189.28 75.93 89.21c-12.28-12.28-32.19-12.28-44.48 0L9.21 111.45c-12.28 12.28-12.28 32.19 0 44.48L109.28 256 9.21 356.07c-12.28 12.28-12.28 32.19 0 44.48l22.24 22.24c12.28 12.28 32.2 12.28 44.48 0L176 322.72l100.07 100.07c12.28 12.28 32.2 12.28 44.48 0l22.24-22.24c12.28-12.28 12.28-32.19 0-44.48L242.72 256z"></path><!----></svg><!----></div><!----></div> <div class="toast-text svelte-1lj56nd"></div> <div class="toast-progress svelte-1lj56nd"><div class="toast-progress-bar svelte-1lj56nd" style="
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