Opened a bug report FB9929569
Similar issue using Carthage. I do not see an attempt to even install brew:
'''
source /Volumes/Task/ci_build.env && source /Volumes/Task/ci_plan.env && cd /Volumes/workspace/repository/ci_scripts && bash /Volumes/workspace/repository/ci_scripts/ci_post_clone.sh
/Volumes/workspace/repository/ci_scripts/ci_post_clone.sh: line 7: brew: command not found
./build_framework.sh: line 22: carthage: command not found
'''
This is new in the last few days. Prior to this I had no issues with this ci script downloading and installing homebrew and carthage.