Yasuhito FUTATSUKI wrote on Sat, Jan 23, 2021 at 01:57:07 +0900:
> Parhaps it is a missed one, that should be fixed :)
>
> With this patch, even if environment variable PYTHON pointed to Python 2,
> the configure script searches Python 3 at first. I'm irresolute that
> it is what it should be or not, and we should add --with-python argment
> to specify Python interpreter explicitly for this purpose or not.
A Unix program should do what it was told and exit silently, or else fail
loudly (with non-empty stderr and a non-zero exit code). "Silently do
something other than I was instructed" would be a bug.
Thus, if the admin points to py2, then we should either use py2 or abort the
build. It's their system, not ours.
If we think the value of some envvar or --option is likely to be a mistake or
unintended configuration, we can print a warning. In extreme cases, we can
even require some sort of opt-in switch, such as --enable-broken-httpd-auth;
however, this amounts to second-guessing the admin, so it's not usually done.
(By the way, if I'm reading build/ac-macros/apache.m4 correctly, there's a bug
in the implementation of that configure flag: it sets $broken_httpd_auth but
tests $enable_broken_httpd_auth. Either I'm misreading the code, or nobody
ever used that flag.)
As to this specific case, here are some ideas:
- We could deprecate $PYTHON and --with-python and require the admin to use
envvars or configure option names that identify the py major version
explicitly: e.g., ${PYTHON2}/${PYTHON3} or --with-python2/--with-python3.
The logic for how to arbitrate among $PYTHON/--with-py2/--with-py3, when more
than one of them is set/passed, would have to be designed.
- Print a warning at the end of configure if py2 was selected automatically
(where "automatically" means, say, "neither via --with-python2 nor by setting
$PYTHON to a value whose basename contains the substring 'python2'").
Makes sense?
Cheers,
Daniel
> [[[
> configure: Search Python 3 before searching Python 2 for tests suite.
>
> * build/find_python.sh: Add option to specify version to search for.
>
> * configure.ac: Search Python 3 before searching Python 2 for tests suite.
> ]]]
>
> Cheers,
> --
> Yasuhito FUTATSUKI <[email protected]>
> Index: build/find_python.sh
> ===================================================================
> --- build/find_python.sh (revision 1885802)
> +++ build/find_python.sh (working copy)
> @@ -21,11 +21,28 @@
> #
>
> # Required version of Python
> -VERSION=${1:-0x2070000}
> +case $1 in
> + -2)
> + CANDIDATE="$PYTHON $PYTHON2 python python2"
> + MIN_VER=${2:-0x2070000}
> + MAX_VER="0x3000000"
> + break
> + ;;
> + -3)
> + CANDIDATE="$PYTHON $PYTHON3 python python3"
> + MIN_VER=${2:-0x3000000}
> + MAX_VER="0xffffffff"
> + ;;
> + *)
> + CANDIDATE="$PYTHON $PYTHON3 python python3 $PYTHON2 python2"
> + MIN_VER=${1:-0x2070000}
> + MAX_VER="0xffffffff"
> +esac
>
> -for pypath in "$PYTHON" "$PYTHON2" "$PYTHON3" python python2 python3; do
> +for pypath in $CANDIDATE; do
> if [ "x$pypath" != "x" ]; then
> - DETECT_PYTHON="import sys;sys.exit((sys.hexversion < $VERSION) and 1 or
> 0)"
> + DETECT_PYTHON="import sys;\
> + sys.exit(0 if $MIN_VER <= sys.hexversion < $MAX_VER else
> 1)"
> if "$pypath" -c "$DETECT_PYTHON" >/dev/null 2>/dev/null; then
> echo $pypath
> exit 0
> Index: configure.ac
> ===================================================================
> --- configure.ac (revision 1885802)
> +++ configure.ac (working copy)
> @@ -1303,15 +1303,22 @@
> # Python: Used for testsuite
> AC_ARG_VAR([PYTHON], [Python interpreter command])
>
> -PYTHON="`$abs_srcdir/build/find_python.sh`"
> -if test -z "$PYTHON"; then
> - AC_MSG_WARN([Python 2.7 or later is required to run the testsuite.])
> - AC_MSG_WARN([])
> - AC_MSG_WARN([If you have a suitable Python installed, but not on the])
> - AC_MSG_WARN([PATH, set the environment variable PYTHON to the full path])
> - AC_MSG_WARN([to the Python executable, and re-run configure])
> - PYTHON=none
> +detected_python="`$abs_srcdir/build/find_python.sh -3`"
> +if test -z "$detected_python"; then
> + detected_python="`$abs_srcdir/build/find_python.sh -2`"
> + if test -z "$detected_python"; then
> + AC_MSG_WARN([Python 2.7 or later is required to run the testsuite.])
> + AC_MSG_WARN([])
> + AC_MSG_WARN([If you have a suitable Python installed, but not on the])
> + AC_MSG_WARN([PATH, set the environment variable PYTHON to the full path])
> + AC_MSG_WARN([to the Python executable, and re-run configure])
> + detected_python=none
> + else
> + AC_MSG_WARN([We recommend you to use Python 3 or later])
> + AC_MSG_WARN([but only Python 2.7 is detected.])
> + fi
> fi
> +PYTHON="$detected_python"
> AC_SUBST(PYTHON)
>
> # The minimum version for the JVM runtime for our Java bytecode.
