Error during `make` on for non-specified python2 path: "python2: bad interpreter"

[Freso]

Using PYTHON=python2for the make process of morituri, this error is encountered:

Making all in bash_completion.d
make[2]: Entering directory '[...]/morituri/etc/bash_completion.d'
PYTHONPATH=../..:$PYTHONPATH ./bash-compgen \
    rip morituri.rip.main.Rip > rip
/bin/sh: ./bash-compgen: python2: bad interpreter: No such file or directory
Makefile:457: recipe for target 'rip' failed
make[2]: *** [rip] Error 126

It used to work fine, but OTOH, specifying the full path (e.g., PYTHON=/usr/bin/python2) seems to work, so not sure if it is worth spending energy on.

[thomasvs]

a patch was merged to change from AS_PYTHON to AM_PYTHON which likely affected this. Looking at its code, it indeed expects PYTHON to be set to a full path.

I'd say that specifying it relatively before was an unintended side effect, so I suggest we close this?