TravisCI changed their default macOS image from 10.10 to 10.11 [1].
Unfortunately the HTTPD tests do not run out of the box using the
pre-installed Apache web server anymore. Therefore we enable these
tests only for Linux and disable them for macOS.

[1] https://blog.travis-ci.com/2016-10-04-osx-73-default-image-live/Signed-off-by: NLars Schneider <larsxschneider@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Install the "apache" package to run the Git web server tests on
Travis-CI Linux build machines. The tests are already executed on OS X
build machines since the apache web server is installed by default.
Signed-off-by: NLars Schneider <larsxschneider@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

As this developer has no access to MacOSX developer setups anymore,
Travis becomes the best bet to run performance tests on that OS.

However, on MacOSX /usr/bin/time is that good old BSD executable that
no Linux user cares about, as demonstrated by the perf-lib.sh's use
of GNU-ish extensions. And by the hard-coded path.

Let's just work around this issue by using gtime on MacOSX, the
Homebrew-provided GNU implementation onto which pretty much every
MacOSX power user falls back anyway.

To help other developers use Travis to run performance tests on
MacOSX, the .travis.yml file now sports a commented-out line that
installs GNU time via Homebrew.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: NLars Schneider <larsxschneider@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Install the "git-svn" package to make the Perl SVN libraries available
to the Git SVN tests on Travis-CI Linux build machines.
Signed-off-by: NLars Schneider <larsxschneider@gmail.com>
Signed-off-by: NEric Wong <e@80x24.org>

Build documentation as separate Travis CI job to check for
documentation errors.
Signed-off-by: NLars Schneider <larsxschneider@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The Git Travis CI OSX build always installs the latest versions of Git LFS and
Perforce via brew and the Linux build installs fixed versions. Consequently new
LFS/Perforce versions can break the OS X build even if there is no change in
Git.
Signed-off-by: NLars Schneider <larsxschneider@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NLars Schneider <larsxschneider@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We assume Git developers have a reasonably modern compiler and recommend
them to enable the DEVELOPER makefile knob to ensure their patches are
clear of all compiler warnings the Git core project cares about.

Enable the DEVELOPER makefile knob in the Travis-CI build.
Suggested-by: NJeff King <peff@peff.net>
Signed-off-by: NLars Schneider <larsxschneider@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Set `sudo: false` to explicitly use the (faster) container-based
infrastructure for the Travis-CI Linux build.

More info:
https://docs.travis-ci.com/user/ci-environment/#Virtualization-environmentsSigned-off-by: NLars Schneider <larsxschneider@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The Travis-CI machines are in a clean state in the beginning of every run
(transient by default). Use the Travis-CI cache feature to make the prove
state persistent across consecutive Travis-CI runs on the same branch.
This allows to run previously failed tests first and run remaining tests
in slowest to fastest order. As a result it is less likely that Travis-CI
needs to wait for a single test at the end which speeds up the test suite
execution by ~2 min.

Travis-CI can only cache entire directories. Prove stores the .prove file
always in the t/ directory but we don't want to cache the entire t/ directory.
Therefore we create a symlink from $HOME/travis-cache/.prove to t/.prove and
cache the $HOME/travis-cache directory.

Unfortunately the cache feature is only available (for free) on the
Travis-CI Linux environment.
Suggested-by: NJeff King <peff@peff.net>
Signed-off-by: NLars Schneider <larsxschneider@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The tests are currently executed on "Ubuntu 12.04 LTS Server Edition
64 bit" and on "OS X Mavericks" using gcc and clang.

Perforce and Git-LFS are installed and therefore available for the
respective tests.
Signed-off-by: NLars Schneider <larsxschneider@gmail.com>
Signed-off-by: NJeff King <peff@peff.net>