Try fcntl only fix for documentation build

re-added mechanism to catch build failure which
would not work running through pv.

[ci docs] [ci all]

tests/travis/travis.yml

@@ -75,7 +75,6 @@ install:
   # builds.
   # Requires 'sudo' on Travis; i.e. not compatible with container builds.
   # pandoc is required for nbconvert in docs; gsl and xpm are for atomeye.
-  # pv stops truncated logs https://github.com/travis-ci/travis-ci/issues/8189
   - if [ "${RUN}" == "true" ]; then
       sudo add-apt-repository -y "ppa:ubuntu-toolchain-r/test";
       sudo apt-get -yq update;
@@ -90,8 +89,7 @@ install:
                               libhdf5-serial-dev
                               pandoc
                               libgsl0-dev
-                              libxpm-dev
-                              pv;
+                              libxpm-dev;
     fi
 
   # If build uses a different GCC, then install it and put
@@ -139,12 +137,10 @@ script:
 after_success:
   # There is no notification if the docs fail to build,
   # so cause a failure by timeout using a long sleep :)
-  # NOTE: Temporarily disabled this mechanism so we can get the whole output of build_docs - mv
-  # fcntl, pv and sleep added due to https://github.com/travis-ci/travis-ci/issues/8189
+  # fcntl added due to https://github.com/travis-ci/travis-ci/issues/8189
   - python -c "import fcntl; fcntl.fcntl(1, fcntl.F_SETFL, 0)"
   - if [ "${DOCS}" == "true" ] && [ ${TRAVIS_PYTHON_VERSION} == 2.7 ]; then
-      tests/travis/build_docs.sh | pv -q -L 3k;
-      sleep 2m;
+      tests/travis/build_docs.sh || sleep 11m;
     fi
 
 # Public and private docker images with GAP, pushed from here