lcov/geninfo/genhtml error messages - what do they mean/what should you do about them

[henry2cox]

Hi -
While adding more 'ignorable errors' to the tools, I realized that the message wording is not always so great, and that it is probably unclear what you should do when/if you see a particular message.

Thus: opened a new discussion subject to try to help you figure it out :-)

At least for the moment, this is going to be demand driven. If you see something and want clarification - or you see something that you think other users might not understand and want to clarify for them: post here.

At some point: we may have a full set of messages - and maybe even a full suite of testcases which exhibit each of them.
Sadly: that day is not today.

Henry

[henry2cox]

Someone appears to have asked a question here and then removed it (or github won't show me the comment.
I thought it was possibly useful to others to answer - even if the original query was solved by the the user.

The question:

What can I do to fix the issue? Can I safely ignore this path error?
Reading tracefile /home/user/build/71/Ubu22_lcov_covg_AllCovData.info.
Found 1988 entries.
Reading diff file ../DiffCov/udiff.txt
Reading tracefile /home/user/build/64/Ubu22_lcov_covg_AllCovData.info.
Found 1982 baseline entries.
genhtml: WARNING: (mismatch) source file 'Source/Apps/Test/UnitTests/CPPAPI/stdafx.h' (in both baseline and current .info files) has same basename as 'diff' entries:
'Source/Core/OT/stdafx.h'
Source/Apps/Test/Cpp/TestServer/stdafx.h' - but a different path.
Possible pathname mismatch? Perhaps see "--elide-path-mismatch", "--substitute" and "--build-directory" options in 'man genhtml'
(use "genhtml --ignore-errors mismatch,mismatch ..." to suppress this warning)
genhtml: ERROR: (path) possible path inconsistency in baseline/current/udiff data
(use "genhtml --ignore-errors path ..." to bypass this error)

If you would rather not suppress the message and/or would like to understand or fix the issue:

• when processing a differential coverage report, genhtml expects to find baseline and current coverage information and udiff information for every file.
• if it finds a complete data set for some file, then it knows that it has correctly matched corresponding coverage and diff information.. Call this a 'fully matched' file.
• if it finds an incomplete set: then it worries that it might not have correctly matched the data (for example, because of differences in relative vs absolute path names or due to unexpected version differences). Call this an 'incompletely matched' file
• for each incompletely matched file, looks to see if it can find incompletely matched baseline/current/udiff data for some file which has the same basename but a different path. That file is also incompletely matched - and genhtml thinks that that might be a problem.

What to do about it:

• as suggested in the message, you can ignore the particular error by modifying your command line: genhtml --ignore-errors path ...
• if there really is an incomplete match due to naming: fix the naming issues (see the man page entries for the suggested options).
• if the issue is just that there are no differences in the file such that there is no entry for it in the udiff data: add an empty entry for the file into the udiff data - to tell genheml that you did not expect to see differences. (the gitdiff script does exactly this.)
• if the issue is that you have a udiff entry for a file that isn't part of your project/report: simply remove it (see the --exclude option).