Cannot include Criterion as meson subproject

[tsieprawski]

Hello!

I've tried to use Criterion in my project as meson's wrap-based subproject, and during simplest meson build I got some issues related build scripts using wrong paths. meson.source_root() is used for ci/isdir.py and dependencies, and in a subproject there are unfindable by default:

subprojects/criterion/meson.build:20:0: ERROR: Program or command '/home/tomasz/criterion-bug-source-dir/ci/isdir.py' not found or not executable
subprojects/boxfort/meson.build:19:0: ERROR: Program or command '/home/tomasz/criterion-bug-source-dir/ci/isdir.py' not found or not executable

Thankfully using meson.current_source_dir() is enough - see the below ugly fix. I'll try to produce a pull request for that. :)

Here's the minimal repo I've been able to reproduce this, with the ugly in-place fixes: https://hg.sr.ht/~tsieprawski/criterion-bug-source-dir/

sed -i "s|source_root|current_source_dir|" subprojects/criterion/meson.build
sed -i "s|'\.\.\/dependencies\/nanopb|meson.current_source_dir() + '/../dependencies/nanopb|" subprojects/criterion/src/meson.build
sed -i "s|source_root|current_source_dir|" subprojects/boxfort/meson.build

And the asciinema video: video.cast.zip