Spack is not populating CPATH anymore (e3f97b37e6 (diff-259adc895c0b2e8fca42ffb99d8051eec0712c868d12d8da255d32f1663acdc7)), and downstream packages ([gaudi](1aa7758dbb/var/spack/repos/builtin/packages/gaudi/package.py (L116))) have alrady started to include this in their package.py files. Instead of propagating this to all downstream packages, it tries to address the issue at the source.
e3f97b37e6 (diff-259adc895c0b2e8fca42ffb99d8051eec0712c868d12d8da255d32f1663acdc7)
1aa7758dbb/var/spack/repos/builtin/packages/gaudi/package.py (L116)