When checking for a suitable Python version, try "python2", "python 2.7", "python2.6", etc. before trying "python".
Usually, when AM_PATH_PYTHON is invoked with an argument of the form 2.X, it means that only a Python 2 interpreter should be used, and not a Python 3 interpreter. However, the "python" command invokes a Python 3 interpreter on some systems (see [1]), so if we try "python" first, we may get a Python 3 interpreter when really a Python 2 interpreter is needed. By changing the precedence so that the "python2(.X)" commands are tried first, a Python 2 interpreter will always be used if one is available (and of sufficiently high version). [1] http://www.python.org/dev/peps/pep-0394/ --- m4/python.m4 | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/m4/python.m4 b/m4/python.m4 index 5d9d057..6815ff1 100644 --- a/m4/python.m4 +++ b/m4/python.m4 @@ -37,8 +37,8 @@ AC_DEFUN([AM_PATH_PYTHON], dnl Find a Python interpreter. Python versions prior to 2.0 are not dnl supported. (2.0 was released on October 16, 2000). m4_define_default([_AM_PYTHON_INTERPRETER_LIST], -[python python2 python3 python3.3 python3.2 python3.1 python3.0 python2.7 dnl - python2.6 python2.5 python2.4 python2.3 python2.2 python2.1 python2.0]) +[python2 python2.7 python2.6 python2.5 python2.4 python2.3 python2.1 python2.0 dnl + python python3 python3.2 python3.1 python3.0]) AC_ARG_VAR([PYTHON], [the Python interpreter]) -- 1.8.0.2