opencv @3.1.0_6+python34: Portfile broken for variant +python34

[detlevd (Detlev Droege)]

On macOS 10.11 I installed opencv +python34, but the portfile causes python35 and friends to be installed (alltough for py34 everything is there):

me@mymac> sudo port install opencv +python34
--->  Computing dependencies for opencv
--->  Dependencies to be installed: py35-numpy py35-cython python35 py35-nose py35-setuptools
  ...

Furthermore, the stuff is then installed in .../3.5/lib/python3.5/site-packages where my python 3.4 scripts don't find them.

Compared to earlier versions of the Portfile (opencv @3.1.0_4+python34), instead of explicit variant descriptions, the current one (opencv @3.1.0_6+python34) contains some loop over python versions

set pythonversions {3.4 3.5}
foreach pdv ${pythonversions} {
    set pv [join [lrange [split ${pdv} .] 0 1] ""]
    set conflist ""
    foreach v ${pythonversions} {
      ...

which apparently does not work as expected.

Workaround: delete '3.5' from the 'pythonversions' list to get a working "+python34" variant.

[mf2k (Frank Schima)]

In the future, please Cc the port maintainers (port info --maintainers opencv), if any.

[RJVB (René Bertin)]

My bad, defining variants (or subports) in a loop that set dependencies or configure arguments that contain loop variables can lead to unexpected results, and I've already been bitten by it before. If it's that the fix is easy enough and I'll upload a patch shortly.

detlevd, you seem handy enough to tinker around in Portfiles, could you apply and test the patch when you see it please?

[RJVB (René Bertin)]

fix the +python34 build issue (and removes an inexistant CMake option). A revbump is not required.

[detlevd (Detlev Droege)]

René - thanks for the patch! I applied it to the opencv Portfile and performed an upgrade --force on opencv. Everything works as expected now. No more dependecies on python35 in variant +python34. Scripts using 'import cv2' now work as before. I did not check it for +python35 though.

[mkae (Marko Käning)]

In 26d39ec4/macports-ports:

opencv: fix broken variant handling

revbump to force rebuild due to wrongly spelled configure option

Closes: #53022