bug#30616: automake-1.16: aclocal is unable to process AM_PATH_PYTHON with variable as value

[Thomas Deutschmann]

Hi,

the problem is line

> m4_define_default([am_py_min_ver], m4_ifval([$1], [$1], [2.0]))

Code like

> AM_PATH_PYTHON([$PYTHON_VERSION])

will result in "am_py_min_ver" set to "$PYTHON_VERSION" which is
obviously not a valid value. I.e. the passed argument isn't expanded
when used in the macro.

However, I don't understand why we need the dynamic in the list
creation. From my understanding, GNU Pyconfigure, the implementation
source, provided a macro which requires to set lower and upper bound
("PC_INIT([MIN_VER], [MAX_VER])"). But given that the AM_PATH_PYTHON
public function wasn't changed, we don't need to (better: cannot)
generate the list dynamically. So I would recommend to change this line to

> m4_define_default([am_py_min_ver], [2.0])

This fixes the problem in cryptsetup, util-linux and PythonMagick for
me. And the check still works. I.e. when I remove the minimum Python
version or newer on my system, configure fails like expected.


-- 
Regards,
Thomas Deutschmann / Gentoo Linux Developer
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