Travis-CI times out while attempting to install qt

[tresf]

Attempting to leverage cartr/qt4/qt on a continuous-integration build system the below error occurs:

Direct link to build failure: https://travis-ci.org/LMMS/lmms/jobs/188301347#L630

Downstream script logic: https://github.com/LMMS/lmms/pull/3201/files

  ==> Installing qt from cartr/qt4
  ==> Downloading https://download.qt.io/official_releases/qt/4.8/4.8.7/qt-everywh
  ==> Downloading from http://qt.mirrors.tds.net/qt/official_releases/qt/4.8/4.8.7
  ==> Downloading https://raw.githubusercontent.com/Homebrew/formula-patches/480b7
  ==> Downloading https://raw.githubusercontent.com/cartr/homebrew-qt4/41669527a2a
  ==> Patching
  ==> Applying el-capitan.patch
  patching file src/gui/painting/qpaintengine_mac.cpp
  ==> Applying qsetting-nulls.patch
  patching file src/corelib/io/qsettings.cpp
  patching file src/corelib/io/qsettings_mac.cpp
- patch unexpectedly ends in middle of line
- Hunk #2 succeeded at 276 with fuzz 1.
  ==> ./configure -prefix /usr/local/Cellar/qt/4.8.7_3 -release -opensource -confi
  ==> make
  No output has been received in the last 10m0s, this potentially indicates a stalled build or something wrong with the build itself.
  Check the details on how to adjust your build configuration on: https://docs.travis-ci.com/user/common-build-problems/#Build-times-out-because-no-output-was-received
  The build has been terminated

[cartr]

That patch warning likely isn't the root problem; it happens on any machine that builds the formula from source and doesn't seem to cause issues there.

According to their docs, Travis uses El Capitan by default. Since I don't currently provide binary builds for El Capitan, it's trying to build Qt4 from source and timing out. The easiest way to fix this on your end would be to set osx_image: xcode8.2 to switch to Sierra, for which a binary is available.

[tresf]

@cartr Thanks for the detailed explanation. I was just reading up on stalled builds and Travis offers a 20-minute tickler as well, but your solution will ensure the build occurs quicker, which is a win-win. Thanks!

Closing as this is not an issue with cartr/qt4/qt.