Bug#471513: Please add an example hook for using gcc snapshot easily

[Loïc Minier]

        Hi

On Tue, Mar 18, 2008, Kumar Appaiah wrote:
> Please consider adding an example hook for use with gcc-snapshot build
> testing. I have attached an example which does the needful for gcc,
> g++ and gfortran (which I needed), which you may use to base the
> example.

 Thanks; I think that's a good idea; I have some concerns with the
 implementation though:

> #!/bin/bash
> aptitude -R -y install gcc-snapshot

 This assumes aptitude is installed, but it might not be; consider using
 apt-get instead.  I suggest you look at other sample hooks in pbuilder
 e.g. the lintian one.

> cat > /usr/local/bin/gcc-snapshot <<EOF

 Adding files not tracked by dpkg in the chroot isn't optimal; also,
 can't the gcc-snapshot package provide this wrapper instead?  It
 certainly seems cumbersome to have to create such things for every use
 of gcc-snapshot IMO:

> #!/bin/sh
> LD_LIBRARY_PATH=/usr/lib/gcc-snapshot/lib:$LD_LIBRARY_PATH
> PATH=/usr/lib/gcc-snapshot/bin:$PATH
> gcc "\$@"
> EOF

 Note that this will add "." to LD_LIBRARY_PATH; you should check
 whether LD_LIBRARY_PATH is set before appending/prepending to it.  e.g.
 LD_LIBRARY_PATH="foo${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"

> chmod 755 /usr/local/bin/gcc-snapshot
> cat > /usr/local/bin/g++-snapshot <<EOF
> #!/bin/sh
> LD_LIBRARY_PATH=/usr/lib/gcc-snapshot/lib:$LD_LIBRARY_PATH
> PATH=/usr/lib/gcc-snapshot/bin:$PATH
> g++ "\$@"
> EOF
> chmod 755 /usr/local/bin/g++-snapshot
> cat > /usr/local/bin/gfortran-snapshot <<EOF
> #!/bin/sh
> LD_LIBRARY_PATH=/usr/lib/gcc-snapshot/lib:$LD_LIBRARY_PATH
> PATH=/usr/lib/gcc-snapshot/bin:$PATH
> g++ "\$@"
> EOF
> chmod 755 /usr/local/bin/gfortran-snapshot

 You might want to avoid repetition by wrapping that in a function.

> rm -f /usr/bin/gcc /usr/bin/g++ /usr/bin/gfortran
> ln -s /usr/local/bin/gcc-snapshot /usr/bin/gcc
> ln -s /usr/local/bin/g++-snapshot /usr/bin/g++
> ln -s /usr/local/bin/gfortran-snapshot /usr/bin/gfortran
> #/bin/bash < /dev/tty > /dev/tty

 Instead of rm + ln, you could ln -sf, but again I find it bad style to
 replace dpkg-owned files with your changes.  You could use dpkg-divert,
 or simply install the above as /usr/local/bin/gcc instead of diverting
 /usr/bin/gcc.

   Thanks!
-- 
Loïc Minier