Re: [PATCH] configure: Require Python >= 3.5

[John Snow <jsnow@redhat.com>]

On 10/16/19 6:42 PM, Eduardo Habkost wrote:
> Python 3.5 is the oldest Python version available on our
> supported build platforms, and Python 2 end of life will be 3
> weeks after the planned release date of QEMU 4.2.0.  Drop Python
> 2 support from configure completely, and require Python 3.5 or
> newer.
> 

Which distributions constrain us to 3.5 right now? I know Debian9 is one
of them, but I'm not sure what others exist.

I know I went through and checked a month ago, but I'm very smart and
didn't write it down.

It might be nice to document (somewhere) so we know when we can require
something newer than 3.5 at the next major deprecation event.

> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>


Reviewed-by: John Snow <jsnow@redhat.com>

Thanks!

> ---
>  configure              | 18 ++++--------------
>  tests/Makefile.include |  5 -----
>  2 files changed, 4 insertions(+), 19 deletions(-)
> 
> diff --git a/configure b/configure
> index 08ca4bcb46..870657ec7b 100755
> --- a/configure
> +++ b/configure
> @@ -895,9 +895,9 @@ fi
>  : ${install=${INSTALL-install}}
>  # We prefer python 3.x. A bare 'python' is traditionally
>  # python 2.x, but some distros have it as python 3.x, so
> -# we check that before python2
> +# we check that too
>  python=
> -for binary in "${PYTHON-python3}" python python2
> +for binary in "${PYTHON-python3}" python
>  do
>      if has "$binary"
>      then
> @@ -1824,8 +1824,8 @@ fi
>  
>  # Note that if the Python conditional here evaluates True we will exit
>  # with status 1 which is a shell 'false' value.
> -if ! $python -c 'import sys; sys.exit(sys.version_info < (2,7))'; then
> -  error_exit "Cannot use '$python', Python 2 >= 2.7 or Python 3 is required." \
> +if ! $python -c 'import sys; sys.exit(sys.version_info < (3,5))'; then
> +  error_exit "Cannot use '$python', Python >= 3.5 is required." \
>        "Use --python=/path/to/python to specify a supported Python."
>  fi
>  
> @@ -6456,15 +6456,6 @@ if test "$supported_os" = "no"; then
>      echo "us upstream at qemu-devel@nongnu.org."
>  fi
>  
> -# Note that if the Python conditional here evaluates True we will exit
> -# with status 1 which is a shell 'false' value.
> -if ! $python -c 'import sys; sys.exit(sys.version_info < (3,0))'; then
> -  echo
> -  echo "warning: Python 2 support is deprecated" >&2
> -  echo "warning: Python 3 will be required for building future versions of QEMU" >&2
> -  python2="y"
> -fi
> -
>  config_host_mak="config-host.mak"
>  
>  echo "# Automatically generated by configure - do not modify" >config-all-disas.mak
> @@ -7282,7 +7273,6 @@ echo "INSTALL_DATA=$install -c -m 0644" >> $config_host_mak
>  echo "INSTALL_PROG=$install -c -m 0755" >> $config_host_mak
>  echo "INSTALL_LIB=$install -c -m 0644" >> $config_host_mak
>  echo "PYTHON=$python" >> $config_host_mak
> -echo "PYTHON2=$python2" >> $config_host_mak
>  echo "CC=$cc" >> $config_host_mak
>  if $iasl -h > /dev/null 2>&1; then
>    echo "IASL=$iasl" >> $config_host_mak
> diff --git a/tests/Makefile.include b/tests/Makefile.include
> index 3543451ed3..54ee1f0a2f 100644
> --- a/tests/Makefile.include
> +++ b/tests/Makefile.include
> @@ -1137,7 +1137,6 @@ TESTS_RESULTS_DIR=$(BUILD_DIR)/tests/results
>  AVOCADO_SHOW=app
>  AVOCADO_TAGS=$(patsubst %-softmmu,-t arch:%, $(filter %-softmmu,$(TARGET_DIRS)))
>  
> -ifneq ($(PYTHON2),y)
>  $(TESTS_VENV_DIR): $(TESTS_VENV_REQ)
>  	$(call quiet-command, \
>              $(PYTHON) -m venv --system-site-packages $@, \
> @@ -1146,10 +1145,6 @@ $(TESTS_VENV_DIR): $(TESTS_VENV_REQ)
>              $(TESTS_VENV_DIR)/bin/python -m pip -q install -r $(TESTS_VENV_REQ), \
>              PIP, $(TESTS_VENV_REQ))
>  	$(call quiet-command, touch $@)
> -else
> -$(TESTS_VENV_DIR):
> -	$(error "venv directory for tests requires Python 3")
> -endif
>  
>  $(TESTS_RESULTS_DIR):
>  	$(call quiet-command, mkdir -p $@, \
>