LCOV output started reporting way too small numbers (while Markdown output shows the expected ones)

[hartwork]

Hello!

At some point in time LCOV output started reporting way too small numbers while the Markdown output shows the expected ones. Here is proof and more information:

Markdown output, as expected

$ grcov --binary-path target/debug --source-dir src --ignore '/*' --branch --llvm-path /usr/bin -t markdown -o target/coverage/summary.md .
$ cat target/coverage/summary.md
| file                   | coverage | covered   | missed_lines       |
|------------------------|----------|-----------|--------------------|
| command_line_parser.rs | 100.00%  | 152 / 152 |                    |
| exec.rs                | 100.00%  | 57 / 57   |                    |
| main.rs                | 97.65%   | 208 / 213 | 38, 75, 81, 85, 99 |
| network.rs             | 100.00%  | 157 / 157 |                    |
| logging.rs             | 97.56%   | 160 / 164 | 63-65, 103         |

Total coverage: 98.79%

LCOV output, broken

$ grcov --binary-path target/debug --source-dir src --ignore '/*' --branch --llvm-path /usr/bin -t lcov -o target/coverage/lcov .
$ lcov --list target/coverage/lcov
                              |Lines       |Functions  |Branches    
Filename                      |Rate     Num|Rate    Num|Rate     Num
====================================================================
[/]
command_line_parser.rs        | 7.2%    152| 0.0%    11|    -      0
exec.rs                       |12.3%     57| 0.0%     7|    -      0
logging.rs                    |22.0%    159| 0.0%    33|    -      0
main.rs                       |21.2%    208| 0.0%    44|    -      0
network.rs                    | 7.6%    157| 0.0%    12|    -      0
====================================================================
                        Total:|14.9%    733| 0.0%   107|    -      0

Additional info

• This is with both grcov 0.8.19 and 0.8.20
• This is with LCOV version 2.0-4ubuntu2 and also 2.0-1
• The code base for this was https://github.com/hartwork/rust-for-it/ .
• There is a related bug Coverage reporting in Linux CI started reporting 14.9% instead of the expected >90% hartwork/rust-for-it#171 and pull request Fix coverage reporting (fixes #171) hartwork/rust-for-it#181

Best, Sebastian

[marco-c]

@hartwork could you try with older grcov versions, so we can figure out what caused this?