Prior to this comment the only way to enable the ci mode for the `prebuild.py` script was to pass it the `--ci-build` argument. The ci system doesn't call call prebuild directly, cmake does, so adding this argument via the CI system is impossible. This change adds the `CI_BUILD` environment variable so enabling the ci mode is possible through the CI system.
Prints timing with CI_BUILD environment variable set
% CI_BUILD=foo cmake -G "Unix Makefiles" ../hifi
['/Users/mhard/src/hifi/prebuild.py', '--build-root', '/Users/mhard/src/hifi_build_make']
1556815031 bcab3689-9ec6-49d4-bbdf-05de5840001f sha=3bb61335be
1556815031 bcab3689-9ec6-49d4-bbdf-05de5840001f start
Warning: Environment variable HIFI_VCPKG_BASE not set, using /Users/mhard/hifi/vcpkg
Using vcpkg path /Users/mhard/hifi/vcpkg/c1966b8c
[... snip ...]
Doesn't print timing when CI_BUILD environment variable is unset:
% cmake -G "Unix Makefiles" ../hifi
['/Users/mhard/src/hifi/prebuild.py', '--build-root', '/Users/mhard/src/hifi_build_make']
Warning: Environment variable HIFI_VCPKG_BASE not set, using /Users/mhard/hifi/vcpkg
Using vcpkg path /Users/mhard/hifi/vcpkg/c1966b8c
[... snip ...]
Metric about the times various parts of the build take are great to
have. This change takes us a step in that direction by adding metrics to
the prebuild step of the build process. These metrics are off by
default; use the `--ci-build` option of `prebuild.py` to enable them.
