Distutils/Setuptools/Distribute modify shebangs of installed Python scripts, so
that they
contain path of Python interpreter with version included (e.g.
"#!/usr/bin/python3.2").
This behavior has both advantage and disadvantages:
- Scripts of packages supporting only e.g. Python 2 can be executed (without
necessity
of using of e.g. "python2 /usr/bin/${script}") after activating of e.g.
Python 3.
- Scripts of packages supporting multiple Python versions ignore active
Python version.
- Scripts of packages supporting multiple Python versions cannot be easily
(without
necessity of using of e.g. "python3.1 /usr/bin/${script}") executed with a
Python
version different than active Python version.
The best solution, which removes these 2 disadvantages and preserves the
advantage, seems
to be to rename Python scripts to include Python version [1] in filenames, and
create wrapper
scripts, which call appropriate target scripts [2]. Some files sometimes try to
execute
e.g. "/usr/bin/python /usr/bin/${script}", so wrapper scripts must be
implemented in Python.
Wrapper scripts try to execute "${wrapper_script}-${PYTHON_ABI}" files (e.g.
"py.test" will
execute "py.test-3.1", when Python 3.1 is set as active Python version).
distutils.eclass will automatically rename some scripts [3] in "${D}usr/bin"
and call
the function, which generates wrapper scripts. In case somebody is interested
in reading of
source code of python_generate_wrapper_scripts() function and potential
suggesting of
improvements, I'm attaching this function and 2 example wrapper scripts. I'm
planning to
commit addition of this function in next week.
[1] Actually Python ABI.
[2] Wrapper scripts can also be created for ELF target files (e.g. "mpipython").
[3] Only scripts of packages supporting installation for multiple Python
versions will be
renamed. Scripts, whose filenames end in [[:digit:]]+\.[[:digit:]]+, won't
be renamed.
--
Arfrever Frehtes Taifersar Arahesis
# @FUNCTION: python_generate_wrapper_scripts
# @USAGE: [-E|--respect-EPYTHON] [-f|--force] [-q|--quiet] [--] [files]
# @DESCRIPTION:
# Generate wrapper scripts. Existing files are overwritten only with --force
option.
# If --respect-EPYTHON option is specified, then generated wrapper scripts will
# respect EPYTHON variable at run time.
python_generate_wrapper_scripts() {
local eselect_python_option file force="0" quiet="0" PYTHON_ABI
python2_enabled="0" python2_supported_versions python3_enabled="0"
python3_supported_versions respect_EPYTHON="0"
python2_supported_versions="2.4 2.5 2.6 2.7"
python3_supported_versions="3.0 3.1 3.2"
while (($#)); do
case "$1" in
-E|--respect-EPYTHON)
respect_EPYTHON="1"
;;
-f|--force)
force="1"
;;
-q|--quiet)
quiet="1"
;;
--)
break
;;
-*)
die "${FUNCNAME}(): Unrecognized option '$1'"
;;
*)
break
;;
esac
shift
done
validate_PYTHON_ABIS
for PYTHON_ABI in ${python2_supported_versions}; do
if has "${PYTHON_ABI}" ${PYTHON_ABIS}; then
python2_enabled="1"
fi
done
for PYTHON_ABI in ${python3_supported_versions}; do
if has "${PYTHON_ABI}" ${PYTHON_ABIS}; then
python3_enabled="1"
fi
done
if [[ "${python2_enabled}" == "1" && "${python3_enabled}" == "1" ]];
then
eselect_python_option=
elif [[ "${python2_enabled}" == "1" && "${python3_enabled}" == "0" ]];
then
eselect_python_option="--python2"
elif [[ "${python2_enabled}" == "0" && "${python3_enabled}" == "1" ]];
then
eselect_python_option="--python3"
else
die "${FUNCNAME}(): Unsupported environment"
fi
for file in "$@"; do
if [[ -f "${file}" && "${force}" == "0" ]]; then
die "${FUNCNAME}(): '$1' already exists"
fi
if [[ "${quiet}" == "0" ]]; then
einfo "Generating '${file#${D%/}}' wrapper script"
fi
cat << EOF > "${file}"
#!/usr/bin/env python
# Gentoo '${file##*/}' wrapper script
import os
import re
import subprocess
import sys
EPYTHON_re = re.compile(r"^python(\d+\.\d+)$")
EOF
if [[ "$?" != "0" ]]; then
die "${FUNCNAME}(): Generation of
