Description:

extra/gdb (v 7.9) is currently compiled against python 2. My understanding is that unless there is a good reason to stick with 2, Arch policy is to build against python 3.

I was able to build this package against python 3 using a trivial modification to the existing PKGBUILD.

Since then I have put my gdb through a bunch of tests (tho more are likely in order) and everything seems to work fine. Both versions of python are supported upstream.

Is there some problem with upgrading to python 3 in gdb or would it be better to make a gdb-python3 package in the AUR?

Additional info:
* package version(s)
GNU gdb (GDB) 7.9
Copyright (C) 2015 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-unknown-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word".

* config and/or log files etc.

Here is the modified PKGBUILD

# Maintainer: Allan McRae <allan@archlinux.org>
# Contributor: Jan de Groot <jgc@archlinux.org>

pkgname=gdb
pkgver=7.9
pkgrel=2
pkgdesc='The GNU Debugger'
arch=('i686' 'x86_64')
url="http://www.gnu.org/software/gdb/"
license=('GPL3')
depends=('ncurses' 'expat' 'python' 'xz' 'guile')
makedepends=('texinfo')
backup=('etc/gdb/gdbinit')
install=gdb.install
source=(http://ftp.gnu.org/gnu/gdb/${pkgname}-${pkgver}.tar.xz{,.sig})
sha1sums=('1dabff2168bd8fe3cadf9386e47a47c527ea99ba'
'SKIP')
validpgpkeys=('F40ADB902B24264AA42E50BF92EDB04BFF325CF3') # Joel Brobecker

prepare() {
cd gdb-$pkgver

# hack! - libiberty configure tests for header files using "$CPP $CPPFLAGS"
sed -i "/ac_cpp=/s/\$CPPFLAGS/\$CPPFLAGS -O2/" libiberty/configure
}

build() {
cd gdb-$pkgver

# guile support has a severe bug https://sourceware.org/bugzilla/show_bug.cgi?id=17247
./configure --prefix=/usr --disable-nls \
--with-system-readline \
--with-python=/usr/bin/python3 \
--with-system-gdbinit=/etc/gdb/gdbinit
make
}

package() {
cd gdb-$pkgver
make DESTDIR=$pkgdir install

# install "custom" system gdbinit
install -dm755 $pkgdir/etc/gdb
touch $pkgdir/etc/gdb/gdbinit

# resolve conflicts with binutils
rm $pkgdir/usr/include/{ansidecl,bfd,bfdlink,dis-asm,plugin-api,symcat}.h
rm $pkgdir/usr/share/info/bfd.info
rm $pkgdir/usr/lib/{libbfd,libopcodes}.a
}


Steps to reproduce:

Install gdb :)