Support subdirectory in VCS requirements

[pazeshun]

I want to use subdirectory syntax in requirements.txt to install a python module in a subdirectory of a repository:

-e git+https://github.com/cocodataset/cocoapi.git#egg=pycocotools&subdirectory=PythonAPI

subdirectory syntax is written at https://pip.pypa.io/en/stable/reference/pip_install/#vcs-support
However, I encountered the following error when I ran catkin build:

Traceback (most recent call last):
  File "/opt/ros/kinetic/lib/catkin_virtualenv/combine_requirements", line 85, in <module>
    sys.exit(combine_requirements(**vars(args)))
  File "/opt/ros/kinetic/lib/catkin_virtualenv/combine_requirements", line 56, in combine_requirements
    requirement_string, str(vcs_err), str(semver_err)))
RuntimeError: Could not match requirement -e git+https://github.com/cocodataset/cocoapi.git#egg=pycocotools&subdirectory=PythonAPI for VCS (No match for ^(?P<scheme>git|git\+https|git\+ssh|git\+git|hg\+http|hg\+https|hg\+static-http|hg\+ssh|svn|svn\+svn|svn\+http|svn\+https|svn\+ssh|bzr\+http|bzr\+https|bzr\+ssh|bzr\+sftp|bzr\+ftp|bzr\+lp)://((?P<login>[^/@]+)@)?(?P<path>[^#@]+)(@(?P<revision>[^#]+))?(#egg=(?P<name>[^&]+))?$) or SemVer (Invalid requirement, parse error at "'-e git+h'")
make[2]: *** [generated_requirements.txt] Error 1

#40 doesn't seem to support the subdirectory syntax.

[paulbovbel]

Hi @pazeshun, you're right, that particular argument isn't supported.

Since catkin_virtualenv doesn't actually care about the details of the VCS requirement beyond the package name, it should be a matter of extending the regex to be more permissive. If this use-case interests you, please consider submitting a PR!

[paulbovbel]

Resolved as a side-effect of #55