build-sys: simplify python detection

This allows './configure --enable-most-builds' and 'make distcheck' to
work when both python2 and python3 are installed, and user has set python
version preference using symlink and PATH order.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/configure.ac b/configure.ac
index c7c66bcd8397b78814c53be03a95a5ea416996bf..cbcda46c845cb2199ccb0deb3a504bfef38cee83 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1421,20 +1421,14 @@ AS_IF([test "x$with_python" != xno], [
   # (minimal version is 2) but if major version is explicitly specified by
   # --with-python=2 or --with-python=3 then we look for PKG module "python2" or
   # "python3".
-  pymajor="2"
-  modname="python"
-  AS_IF([test "x$withval" != xno -a "x$withval" != xyes], [
-    pymajor="$withval"
-    modname="python${pymajor}"
-  ])
-  PKG_CHECK_MODULES(PYTHON,[${modname} >= $pymajor],
-                          [have_python=yes
-                           AM_PATH_PYTHON([$pymajor])],
-                          [have_python=no])
+  AS_IF([test "x$withval" != xno -a "x$withval" != xyes],
+       [pymajor="$withval"; PYTHON=python${pymajor}], [pymajor="2"])
+  AM_PATH_PYTHON([$pymajor], [have_python=yes], [have_python=no])
   AS_CASE([$with_python:$have_python],
     [yes:no],
-      [AC_MSG_ERROR([python selected but libpython not found])],
+      [AC_MSG_ERROR([python selected but libpython not found])]
   )
+  PKG_CHECK_MODULES([PYTHON], [python-$PYTHON_VERSION])
 
   UL_BUILD_INIT([pylibmount], [check])
   UL_REQUIRES_HAVE([pylibmount], [python], [libpython])
@@ -1576,7 +1570,8 @@ AC_MSG_RESULT([
        ldflags:           ${LDFLAGS}
        suid ldflags:      ${SUID_LDFLAGS}
 
-       Python:            ${PYTHON_VERSION}
+       Python:            ${PYTHON}
+       Python version:    ${PYTHON_VERSION}
        Python libs:       ${pyexecdir}
 
        Bash completions:  ${with_bashcompletiondir}