mozilla/grcov

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Rust tool to collect and aggregate code coverage data for multiple source files

Stars: 1.4k
Forks: 170
Open beginner issues: 0
Indexed issues: 121
Avg merge: 3d 10h
Merged PRs (30d): 4

Dominant language: Rust
License: MPL-2.0
Last GitHub push: Sep 11, 2026
Latest indexed: Sep 19, 2026
Contributing guide: No contributing guide
Code of conduct: Code of conduct
Beginner labels: help wanted

Beginner friendly Everything

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121 open issues indexed

Remove Rust version divergence when Rust 1.100 hits stable Open

Difficulty 1/5 Under an hour Newbie friendliness 90/100

mozilla/grcov#1525 · Opened Sep 9, 2026
Parser rejects `FN:` records with negative line numbers, then deadlocks when panics happen in worker threads Open

Difficulty 4/5 3-5 days Newbie friendliness 48/100

mozilla/grcov#1514 · Opened Jul 9, 2026
`grcov` can panic on several malformed coverage inputs instead of reporting parse/output errors Open

Difficulty 4/5 3-5 days Newbie friendliness 52/100

mozilla/grcov#1511 · Opened Jun 23, 2026
LCOV parser breaks on DA lines with optional checksum field Open

Difficulty 3/5 1-2 days Newbie friendliness 68/100

mozilla/grcov#1501 · Opened May 21, 2026
How to merge coverage data Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

mozilla/grcov#1491 · Opened Apr 26, 2026
Investigate tcmalloc-better instead of tcmalloc Open

help wanted perf

Difficulty 5/5 Over a week Newbie friendliness 25/100

mozilla/grcov#1379 · Opened Jul 29, 2025
panic at grcov-0.9.1/src/llvm_tools.rs:95 Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mozilla/grcov#1348 · 2 comments · Opened May 7, 2025
gitlab template in `README.md` is wrong Open

Difficulty 1/5 Under an hour Newbie friendliness 50/100

mozilla/grcov#1344 · 1 comment · Opened May 4, 2025
no links to subdirectories in generated html Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

mozilla/grcov#1343 · Opened May 4, 2025
absolute link to `bulma.css` in toplevel document Open

Difficulty 1/5 Under an hour Newbie friendliness 38/100

mozilla/grcov#1342 · 2 comments · Opened May 4, 2025
[ERROR] Error parsing file plain files: Invalid record: 'Attribute line not found' TN: Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

mozilla/grcov#1327 · 5 comments · Opened Apr 11, 2025
Walk source directory in parallel to speed up path rewriting with large repositories Open

perf

Difficulty 4/5 3-5 days Newbie friendliness 38/100

mozilla/grcov#1308 · Opened Apr 4, 2025
Error is too vague when rustc is missing Open

Difficulty 2/5 1-3 hours Newbie friendliness 52/100

mozilla/grcov#1267 · 1 comment · Opened Jan 7, 2025
Raw profile version mismatch, no profile can be merged Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mozilla/grcov#1192 · 6 comments · 1 reaction · Opened Aug 2, 2024
grcov 0.8.19 panics with "`Option::unwrap()` on a `None` value" on Windows Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

mozilla/grcov#1190 · 1 comment · Opened Jul 19, 2024
grcov gives an error to open some unknown file Open

Difficulty 3/5 1-2 days Newbie friendliness 25/100

mozilla/grcov#1185 · Opened Jun 21, 2024
Possible to exclude functions matching a pattern for name Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

mozilla/grcov#1184 · 2 comments · Opened Jun 14, 2024
Cannot generate report from Meson's out-of-tree build with GCC's coverage instrumentation Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mozilla/grcov#1182 · 5 comments · Opened Jun 6, 2024
Question about `--ignore <PATH>` option Open

Difficulty 2/5 1-3 hours Newbie friendliness 25/100

mozilla/grcov#1176 · 1 comment · Opened Feb 16, 2024
Output Location Seems Inconsistent Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

mozilla/grcov#1166 · 1 reaction · Opened Jan 9, 2024
Exit code is 0 even in case of fatal error Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

mozilla/grcov#1160 · 1 reaction · Opened Jan 3, 2024
grcov get more excute times Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

mozilla/grcov#1151 · 1 comment · Opened Dec 11, 2023
Impossible to ignore filenames containing digits Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

mozilla/grcov#1130 · Opened Oct 26, 2023
Evaluate using Profile-Guided Optimization (PGO) and LLVM BOLT Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

mozilla/grcov#1128 · 1 comment · Opened Oct 22, 2023
html report differs from lcov report Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

mozilla/grcov#1103 · 2 comments · 2 reactions · Opened Aug 31, 2023
src/producer.rs:544: No input files found Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

mozilla/grcov#1087 · 3 comments · Opened Aug 2, 2023
Example for C++ coverage processing with different folders for source/notes and coverage data files? Open

Difficulty 2/5 1-3 hours Newbie friendliness 35/100

mozilla/grcov#1072 · 1 comment · Opened Jul 14, 2023
Adding a timout command when running the executable file could cause wrong coverage result Open

Difficulty 4/5 3-5 days Newbie friendliness 28/100

mozilla/grcov#1065 · Opened Jun 27, 2023
Unit tests with Comments Are Displayed as Uncovered Open

Difficulty 4/5 3-5 days Newbie friendliness 30/100

mozilla/grcov#1042 · 1 reaction · Opened May 28, 2023
`-t html` works with `-o ./target/debug/coverage/`, but `-t lcov` doesn't Open

Difficulty 2/5 1-3 hours Newbie friendliness 35/100

mozilla/grcov#1028 · 2 comments · Opened Apr 29, 2023
`--log-level` doesn't work Open

bug

Difficulty 3/5 1-2 days Newbie friendliness 35/100

mozilla/grcov#1024 · 2 reactions · Opened Apr 25, 2023
Grcov create a sub-folder inside the same previous output folder when the output type is html Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

mozilla/grcov#1020 · 7 comments · 3 reactions · Opened Apr 22, 2023
grcov sometimes takes very long to execute Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mozilla/grcov#1013 · 26 comments · 1 reaction · Opened Apr 11, 2023
uncover reports on `#[cfg_attr]` Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mozilla/grcov#1012 · Opened Apr 10, 2023
More detail/documentation for "functions" coverage Open

Difficulty 5/5 Over a week Newbie friendliness 30/100

mozilla/grcov#971 · 1 comment · 2 reactions · Opened Mar 1, 2023
Output format to summarize gcno information Open

mozilla/grcov#966 · 1 assignee · Opened Feb 21, 2023
Html report should show the branch count per line Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

mozilla/grcov#964 · 3 reactions · Opened Feb 20, 2023
hits for line number reported as unsigned max int Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

mozilla/grcov#960 · 2 comments · Opened Feb 8, 2023
cargo test failed in windows Open

Difficulty 3/5 1-2 days Newbie friendliness 25/100

mozilla/grcov#956 · Opened Feb 2, 2023
Log file path on parser error? Open

Difficulty 2/5 1-3 hours Newbie friendliness 35/100

mozilla/grcov#953 · Opened Jan 12, 2023
Line coverage showing incorrect values when `tracing::instrument` attribute is used Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

mozilla/grcov#950 · 4 reactions · Opened Jan 9, 2023
Outputting files in a JUnit format Open

good-first-bug

Difficulty 4/5 3-5 days Newbie friendliness 25/100

mozilla/grcov#909 · 1 comment · Opened Oct 30, 2022
Error parsing gcov branch information with negative count Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

mozilla/grcov#908 · 4 comments · Opened Oct 26, 2022
How to compute coverage of new/modified code with grcov for rust？ Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

mozilla/grcov#890 · 4 comments · Opened Sep 21, 2022
Behavior when no source directory is specified Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mozilla/grcov#883 · 1 comment · 1 reaction · Opened Sep 12, 2022
Coverage display on codecov.io does not match locally-generated HTML report Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mozilla/grcov#860 · 1 comment · 4 reactions · Opened Jul 8, 2022
grcov fails to build on Windows with `undefined reference to __imp__ZN15crossbeam_` Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

mozilla/grcov#849 · Opened Jun 21, 2022
Line coverage breaks for untouched test if another fails Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mozilla/grcov#821 · 1 comment · Opened May 1, 2022
lcov output on Windows is broken when depending on some crate Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mozilla/grcov#808 · 1 comment · Opened Apr 9, 2022
grcov panics if used on cargo Open

Difficulty 3/5 1-2 days Newbie friendliness 32/100

mozilla/grcov#804 · 2 comments · Opened Apr 4, 2022

mozilla/grcov

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