Merge pull request #2692 from rust-lang/tshepang/fuzzing

small improvements to fuzzing.md

Author: tshepang

src/fuzzing.md

@@ -5,8 +5,8 @@
 For the purposes of this guide, *fuzzing* is any testing methodology that
 involves compiling a wide variety of programs in an attempt to uncover bugs in rustc.
 Fuzzing is often used to find internal compiler errors (ICEs).
-Fuzzing can be beneficial, because it can find bugs before users run into them and
-provide small, self-contained programs that make the bug easier to track down.
+Fuzzing can be beneficial, because it can find bugs before users run into them.
+It also provides small, self-contained programs that make the bug easier to track down.
 However, some common mistakes can reduce the helpfulness of fuzzing and end up
 making contributors' lives harder.
 To maximize your positive impact on the Rust
@@ -22,7 +22,7 @@ project, please read this guide before reporting fuzzer-generated bugs!
 - Include a reasonably minimal, standalone example along with any bug report
 - Include all of the information requested in the bug report template
 - Search for existing reports with the same message and query stack
-- Format the test case with `rustfmt`, if it maintains the bug
+- Format the test case with `rustfmt`
 - Indicate that the bug was found by fuzzing
 
 *Please don't:*
@@ -36,15 +36,17 @@ project, please read this guide before reporting fuzzer-generated bugs!
 If you're not sure whether or not an ICE is a duplicate of one that's already
 been reported, please go ahead and report it and link to issues you think might be related.
 In general, ICEs on the same line but with different *query stacks* are usually distinct bugs.
-For example, [#109020][#109020] and [#109129][#109129] had similar error messages:
+For example, [#109020] and [#109129] had similar error messages:
 
 ```
 error: internal compiler error: compiler/rustc_middle/src/ty/normalize_erasing_regions.rs:195:90: Failed to normalize <[closure@src/main.rs:36:25: 36:28] as std::ops::FnOnce<(Emplacable<()>,)>>::Output, maybe try to call `try_normalize_erasing_regions` instead
 ```
+
 ```
 error: internal compiler error: compiler/rustc_middle/src/ty/normalize_erasing_regions.rs:195:90: Failed to normalize <() as Project>::Assoc, maybe try to call `try_normalize_erasing_regions` instead
 ```
-but different query stacks:
+
+However, they have different query stacks:
 ```
 query stack during panic:
 #0 [fn_abi_of_instance] computing call ABI of `<[closure@src/main.rs:36:25: 36:28] as core::ops::function::FnOnce<(Emplacable<()>,)>>::call_once - shim(vtable)`
@@ -64,7 +66,7 @@ end of query stack
 
 When building a corpus, be sure to avoid collecting tests that are already known to crash rustc.
 A fuzzer that is seeded with such tests is more likely to
-generate bugs with the same root cause, wasting everyone's time.
+generate bugs with the same root cause.
 The simplest way to avoid this is to loop over each file in the corpus, see if it causes an
 ICE, and remove it if so.
 
@@ -73,14 +75,14 @@ To build a corpus, you may want to use:
 - The rustc/rust-analyzer/clippy test suites (or even source code) --- though avoid
   tests that are already known to cause failures, which often begin with comments
   like `//@ failure-status: 101` or `//@ known-bug: #NNN`.
-- The already-fixed ICEs in the archived [Glacier][glacier] repository --- though
+- The already-fixed ICEs in the archived [Glacier] repository --- though
   avoid the unfixed ones in `ices/`!
 
 [glacier]: https://github.com/rust-lang/glacier
 
 ## Extra credit
 
-Here are a few things you can do to help the Rust project after filing an ICE.
+Here are a few things you can do to help the Rust project after filing an ICE:
 
 - [Bisect][bisect] the bug to figure out when it was introduced.
   If you find the regressing PR / commit, you can mark the issue with the label `S-has-bisection`.
@@ -135,19 +137,18 @@ Of course, it's best to try multiple build configurations and see
 what actually results in superior throughput.
 
 You may want to build rustc from source with debug assertions to find
-additional bugs, though this is a trade-off: it can slow down fuzzing by
+additional bugs, though this can slow down fuzzing by
 requiring extra work for every execution.
 To enable debug assertions, add this to `bootstrap.toml` when compiling rustc:
 
 ```toml
-[rust]
-debug-assertions = true
+rust.debug-assertions = true
 ```
 
-ICEs that require debug assertions to reproduce should be tagged 
-[`requires-debug-assertions`][requires-debug-assertions].
+ICEs that require debug assertions to reproduce should be tagged
+[`requires-debug-assertions`].
 
-[requires-debug-assertions]: https://github.com/rust-lang/rust/labels/requires-debug-assertions
+[`requires-debug-assertions`]: https://github.com/rust-lang/rust/labels/requires-debug-assertions
 
 ## Existing projects