twig: update and bootstrap for PHP7.0 support

[Nish Aravamudan]

With only PHP7.0 planned on being in the archive, need to update the build dependencies of the src:twig package, as well as drop support for the C extension (cf. https://github.com/twigphp/Twig/issues/1695).

Additionally, in order to remove PHP5 from the archive, a set of build-dependency
loops need to be bootstrapped, in particular to not depend on phpunit.

[Nish Aravamudan (nacc)]

This debdiff resolves the build issues (testcase segfault & failures) by avoiding those tests for now. I've filed upstream issues to see if we can get help resolving them to put the tests back.

[Steve Langasek (vorlon)]

twig 1.23.1-1ubuntu2 has already been uploaded. Please provide a debdiff for a 1.23.1-1ubuntu3 version relative to this.

[Nish Aravamudan (nacc)]

Note the build currently is failing to start, due to missing a class that has been moved to a new binary package (php-xml). Once that has been updated (1.23.1-1ubuntu3), I think the tests will still fail, but I'm debugging it now. but it might be an upstream PHP issue (https://bugs.php.net/bug.php?id=71659).

[Steve Langasek (vorlon)]

twig 1.23.1-1ubuntu3 uploaded.

[Nish Aravamudan (nacc)]

twig (1.23.1-1ubuntu4) xenial; urgency=medium

  * Add php-mbstring as build-dep and tests dep (LP: #1544276).
  * Run known segfaulting Twig tests in a separate process as a
    short-term workaround for:
    https://bugs.exim.org/show_bug.cgi?id=1803 /
    https://bugs.php.net/bug.php?id=71659.
  * Drop: Add php-xml as build-dep and tests dep, as the version of
    phpunit specified depends on php-xml.

 -- Nishanth Aravamudan <email address hidden> Wed, 24 Feb 2016 11:40:43 -0800

The second entry in the changelog will ideally be reverted before too long, but we need some upstream help to figure out exactly what's going on.

[Steve Langasek (vorlon)]

On Wed, Mar 02, 2016 at 08:45:03PM -0000, Nish Aravamudan wrote:
> ** Attachment added: "twig_1.23.1-1ubuntu3.1.23.1-1ubuntu4.debdif"
> https://bugs.launchpad.net/ubuntu/+source/twig/+bug/1544276/+attachment/4586973/+files/twig_1.23.1-1ubuntu3.1.23.1-1ubuntu4.debdif

Uploading, with one minor adjustment - the build-dependency on phpunit does
not need to be versioned. The xenial build will always use the most recent
version of the package in the archive, and build-dependencies should not be
versioned to work around bugs in older versions of the package.

The correct package relationship to work around the incompatibility between
older phpunit package and newer php-cli is for php-cli to declare a Breaks:
on older versions of phpunit. But this is not strictly required.

[Nish Aravamudan (nacc)]

Thanks Steve, what you wrote makes sense to me. I will do my best to work on the pcre bug upstream and see if we can't get it figured out -- luckily we've reproduced it in a few environments, so I don't think it's exclusively a php7 in ubuntu problem.

[Launchpad Janitor (janitor)]

This bug was fixed in the package twig - 1.23.1-1ubuntu4

---------------
twig (1.23.1-1ubuntu4) xenial; urgency=medium

  * Add php-mbstring as build-dep and tests dep (LP: #1544276).
  * Run known segfaulting Twig tests in a separate process as a
    short-term workaround for:
    https://bugs.exim.org/show_bug.cgi?id=1803 /
    https://bugs.php.net/bug.php?id=71659.
  * Drop: Add php-xml as build-dep and tests dep, as the version of
    phpunit specified depends on php-xml.

 -- Nishanth Aravamudan <email address hidden> Wed, 24 Feb 2016 11:40:43 -0800

[Nish Aravamudan (nacc)]

Steve, once/if we provide a php7.0 with the fix that removes the need for the workaround, we can drop it; do you want a debdiff at that point so we minimize our delta?

[Steve Langasek (vorlon)]

On Wed, Mar 16, 2016 at 06:46:34PM -0000, Nish Aravamudan wrote:
> Steve, once/if we provide a php7.0 with the fix that removes the need
> for the workaround, we can drop it; do you want a debdiff at that point
> so we minimize our delta?

There's no urgency. I'm equally happy for this to be a best-effort
sponsorship to reduce the delta before 16.04, or just something we clean up
in the next merge in 16.10.