ci: automatically clear config.cache if it cannot be used

Summary:
if env vars change between runs then the cache is invalidated, causing
configure to print a very specific error

by running a separate script to catch this error, the build can detect
and clear the cache when necessary to avoid having to manually disable
the cache when changing build settings
Depends on D6697

Reviewers: stefan_schmidt, bu5hm4n

Reviewed By: bu5hm4n

Subscribers: bu5hm4n, cedric, #committers

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D6732

.ci/ci-configure.sh

@@ -57,7 +57,7 @@ if [ "$DISTRO" != "" ] ; then
   travis_fold configure "configure $OPTS"
   docker exec --env MAKEFLAGS="-j5 -rR" --env EIO_MONITOR_POLL=1 --env CC="ccache gcc" \
     --env CXX="ccache g++" --env CFLAGS="-fdirectives-only" --env CXXFLAGS="-fdirectives-only" \
-    --env LD="ld.gold" $(cat $HOME/cid) sh -c "./configure $OPTS || cat config.log"
+    --env LD="ld.gold" $(cat $HOME/cid) sh -c ".ci/configure.sh $OPTS"
   travis_endfold configure
 else
   OSX_COPTS="--disable-cxx-bindings --with-tests=regular --disable-dependency-tracking -C"
@@ -78,6 +78,6 @@ else
   autoreconf -iv
   travis_endfold autoreconf
   travis_fold configure "configure $OSX_COPTS"
-  ./configure $OSX_COPTS || cat config.log
+  .ci/configure.sh $OSX_COPTS
   travis_endfold configure
 fi

.ci/configure.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+
+set -o pipefail
+export TEST_VAR=1
+if ! ./configure $@ | tee -a configlog ; then
+  if grep -q 'configure: error: changes in the environment can compromise the build' configlog ; then
+    echo "clearing config.cache and retrying..."
+    rm -f configlog config.cache
+    ./configure $@
+  fi
+fi

.travis.yml

@@ -84,6 +84,11 @@ before_script:
       fi
 
   - .ci/ci-ccache-stats.sh
+  - |
+       if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then
+         cp $HOME/cachedir/config.cache . || true
+       fi
+
 
 script:
   - .ci/ci-configure.sh "$CI_BUILD_TYPE"