ccls re-index files when compiler starts with '/bin'

[zsrkmyn]

Observed behavior

test.cpp

#include <exception>

compile_commands.json

[{
"directory": "/tmp/test_ccls",
"command": "/bin/g++ -c /tmp/test_ccls/test.cpp",
"file": "/tmp/test_ccls/test.cpp"
}]

Run ccls twice

$ ccls --index=. -v=1 |& grep timestamp
$ ccls --index=. -v=1 |& grep timestamp
11:40:30 indexer15        pipeline.cc:286 V(1) timestamp changed for /tmp/test_ccls/test.cpp via /include/c++/9/exception

Note that the include path is wrong -- /include/c++/9/exception actually doesn't exists, so the mtime here is none, leading to the re-indexing.

If I change the '/bin/g++' to '/usr/bin/g++', the include patch will be correct, and ccls works fine.

Expected behavior

There should be no re-indexing in the 2nd run.

System information

• ccls version: 0.20210330-10-gb28cec18
• clang version: g2fcdd685bd02
• OS: Ubuntu 20.04.2 LTS