view contrib/mercurial.spec @ 27142:060f83d219b9

extensions: refuse to load extensions if minimum hg version not met

As the author of several 3rd party extensions, I frequently see bug
reports from users attempting to run my extension with an old version
of Mercurial that I no longer support in my extension. Oftentimes, the
extension will import just fine. But as soon as we run extsetup(),
reposetup(), or get into the guts of a wrapped function, we encounter
an exception and abort. Today, Mercurial will print a message about
extensions that don't have a "testedwith" declaring explicit
compatibility with the current version.

The existing mechanism is a good start. But it isn't as robust as I
would like. Specifically, Mercurial assumes compatibility by default.
This means extension authors must perform compatibility checking in
their extsetup() or we wait and see if we encounter an abort at
runtime. And, compatibility checking can involve a lot of code and
lots of error checking. It's a lot of effort for extension authors.

Oftentimes, extension authors know which versions of Mercurial there
extension works on and more importantly where it is broken.

This patch introduces a magic "minimumhgversion" attribute in
extensions. When found, the extension loading mechanism will compare
the declared version against the current Mercurial version. If the
extension explicitly states we require a newer Mercurial version, a
warning is printed and the extension isn't loaded beyond importing
the Python module. This causes a graceful failure while alerting
the user of the compatibility issue.

I would be receptive to the idea of making the failure more fatal.
However, care would need to be taken to not criple every hg command.
e.g. the user may use `hg config` to fix the hgrc and if we aborted
trying to run that, the user would effectively be locked out of `hg`!

A potential future improvement to this functionality would be to catch
ImportError for the extension/module and parse the source code for
"minimumhgversion = 'XXX'" and do similar checking. This way we could
give more information about why the extension failed to load.

%global emacs_lispdir %{_datadir}/emacs/site-lisp

%define withpython %{nil}

%if "%{?withpython}"

%global pythonver %{withpython}
%global pythonname Python-%{withpython}
%global docutilsname docutils-0.12
%global docutilsmd5 4622263b62c5c771c03502afa3157768
%global pythonhg python-hg
%global hgpyprefix /opt/%{pythonhg}
# byte compilation will fail on some some Python /test/ files
%global _python_bytecompile_errors_terminate_build 0

%else

%global pythonver %(python -c 'import sys;print ".".join(map(str, sys.version_info[:2]))')

%endif

Summary: A fast, lightweight Source Control Management system
Name: mercurial
Version: snapshot
Release: 0
License: GPLv2+
Group: Development/Tools
URL: https://mercurial-scm.org/
Source0: %{name}-%{version}-%{release}.tar.gz
%if "%{?withpython}"
Source1: %{pythonname}.tgz
Source2: %{docutilsname}.tar.gz
%endif
BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root

BuildRequires: make, gcc, gettext
%if "%{?withpython}"
BuildRequires: readline-devel, openssl-devel, ncurses-devel, zlib-devel, bzip2-devel
%else
BuildRequires: python >= 2.6, python-devel, python-docutils >= 0.5
Requires: python >= 2.6
%endif
# The hgk extension uses the wish tcl interpreter, but we don't enforce it
#Requires: tk

%description
Mercurial is a fast, lightweight source control management system designed
for efficient handling of very large distributed projects.

%prep

%if "%{?withpython}"
%setup -q -n mercurial-%{version}-%{release} -a1 -a2
# despite the comments in cgi.py, we do this to prevent rpmdeps from picking /usr/local/bin/python up
sed -i '1c#! /usr/bin/env python' %{pythonname}/Lib/cgi.py
%else
%setup -q -n mercurial-%{version}-%{release}
%endif

%build

%if "%{?withpython}"

PYPATH=$PWD/%{pythonname}
cd $PYPATH
./configure --prefix=%{hgpyprefix}
make all %{?_smp_mflags}
cd -

cd %{docutilsname}
LD_LIBRARY_PATH=$PYPATH $PYPATH/python setup.py build
cd -

# verify Python environment
LD_LIBRARY_PATH=$PYPATH PYTHONPATH=$PWD/%{docutilsname} $PYPATH/python -c 'import sys, zlib, bz2, ssl, curses, readline'

# set environment for make
export PATH=$PYPATH:$PATH
export LD_LIBRARY_PATH=$PYPATH
export CFLAGS="-L $PYPATH"
export PYTHONPATH=$PWD/%{docutilsname}

%endif

make all

%install
rm -rf $RPM_BUILD_ROOT

%if "%{?withpython}"

PYPATH=$PWD/%{pythonname}
cd $PYPATH
make install DESTDIR=$RPM_BUILD_ROOT
# these .a are not necessary and they are readonly and strip fails - kill them!
rm -f %{buildroot}%{hgpyprefix}/lib/{,python2.*/config}/libpython2.*.a
cd -

cd %{docutilsname}
LD_LIBRARY_PATH=$PYPATH $PYPATH/python setup.py install --root="$RPM_BUILD_ROOT"
cd -

PATH=$PYPATH:$PATH LD_LIBRARY_PATH=$PYPATH make install DESTDIR=$RPM_BUILD_ROOT PREFIX=%{hgpyprefix} MANDIR=%{_mandir}
mkdir -p $RPM_BUILD_ROOT%{_bindir}
( cd $RPM_BUILD_ROOT%{_bindir}/ && ln -s ../..%{hgpyprefix}/bin/hg . )
( cd $RPM_BUILD_ROOT%{_bindir}/ && ln -s ../..%{hgpyprefix}/bin/python2.? %{pythonhg} )

%else

make install DESTDIR=$RPM_BUILD_ROOT PREFIX=%{_prefix} MANDIR=%{_mandir}

%endif

install -m 755 contrib/hgk $RPM_BUILD_ROOT%{_bindir}/
install -m 755 contrib/hg-ssh $RPM_BUILD_ROOT%{_bindir}/

bash_completion_dir=$RPM_BUILD_ROOT%{_sysconfdir}/bash_completion.d
mkdir -p $bash_completion_dir
install -m 644 contrib/bash_completion $bash_completion_dir/mercurial.sh

zsh_completion_dir=$RPM_BUILD_ROOT%{_datadir}/zsh/site-functions
mkdir -p $zsh_completion_dir
install -m 644 contrib/zsh_completion $zsh_completion_dir/_mercurial

mkdir -p $RPM_BUILD_ROOT%{emacs_lispdir}
install -m 644 contrib/mercurial.el $RPM_BUILD_ROOT%{emacs_lispdir}/
install -m 644 contrib/mq.el $RPM_BUILD_ROOT%{emacs_lispdir}/

mkdir -p $RPM_BUILD_ROOT/%{_sysconfdir}/mercurial/hgrc.d

%clean
rm -rf $RPM_BUILD_ROOT

%files
%defattr(-,root,root,-)
%doc CONTRIBUTORS COPYING doc/README doc/hg*.txt doc/hg*.html *.cgi contrib/*.fcgi
%doc %attr(644,root,root) %{_mandir}/man?/hg*
%doc %attr(644,root,root) contrib/*.svg
%dir %{_datadir}/zsh/
%dir %{_datadir}/zsh/site-functions/
%{_datadir}/zsh/site-functions/_mercurial
%dir %{_datadir}/emacs/site-lisp/
%{_datadir}/emacs/site-lisp/mercurial.el
%{_datadir}/emacs/site-lisp/mq.el
%{_bindir}/hg
%{_bindir}/hgk
%{_bindir}/hg-ssh
%dir %{_sysconfdir}/bash_completion.d/
%config(noreplace) %{_sysconfdir}/bash_completion.d/mercurial.sh
%dir %{_sysconfdir}/mercurial
%dir %{_sysconfdir}/mercurial/hgrc.d
%if "%{?withpython}"
%{_bindir}/%{pythonhg}
%{hgpyprefix}
%else
%if "%{?pythonver}" != "2.4"
%{_libdir}/python%{pythonver}/site-packages/%{name}-*-py%{pythonver}.egg-info
%endif
%{_libdir}/python%{pythonver}/site-packages/%{name}
%{_libdir}/python%{pythonver}/site-packages/hgext
%endif