Runner on Windows using bash as the shell passes paths with backslash instead of forward slash
when #2841 (closed) was implemented it was noted that this would cause a problem with bash but the comments say it should be tracked as a separate issue which i don't think happened.
Steps to reproduce
Configure a GitLab-runner on windows to use bash as the shell. The variables CI_BUILDS_DIR CI_PROJECT_DIR contain paths like \c\gitlab-runner\builds\akUEDWYx\0\…
These are a strange mix of windows & unix paths and really should use forwardslashes.
This makes it really hard to write script code that works the same on windows and unix which is the main reason for using bash. This is stopping us moving to a GitLab runner newer than 11.6.0