Build folly from the travis before_script

.travis.yml

@@ -82,12 +82,14 @@ before_script:
   - gem install coveralls-lcov
   - lcov --version
   - eval "$COMPILER_EVAL"
+  # Build folly
+  - mkdir build
+  - ./scripts/build_folly.sh build/folly-src build/folly-install
 
 script:
-  - mkdir build
   - cd build
-  - cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE
-          -DRSOCKET_ASAN=$ASAN -DRSOCKET_INSTALL_DEPS=True
+  - cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE -DRSOCKET_ASAN=$ASAN
+          -DCMAKE_PREFIX_PATH=$PWD/folly-install
           -DRSOCKET_BUILD_WITH_COVERAGE=ON ..
   - make -j4
   - lcov --directory . --zerocounters

scripts/build_folly.sh

@@ -9,6 +9,13 @@ if [[ -z $INSTALL_DIR ]]; then
   exit 1
 fi
 
+# Convert INSTALL_DIR to an absolute path so it still refers to the same
+# location after we cd into the build directory.
+case "$INSTALL_DIR" in
+  /*) ;;
+  *) INSTALL_DIR="$PWD/$INSTALL_DIR"
+esac
+
 # If folly was already installed, just return early
 INSTALL_MARKER_FILE="$INSTALL_DIR/folly.installed"
 if [[ -f $INSTALL_MARKER_FILE ]]; then
@@ -28,7 +35,11 @@ fi
 
 mkdir -p "$CHECKOUT_DIR/_build"
 cd "$CHECKOUT_DIR/_build"
-cmake "-DCMAKE_INSTALL_PREFIX=${INSTALL_DIR}" ..
+if ! cmake "-DCMAKE_INSTALL_PREFIX=${INSTALL_DIR}" ..; then
+    echo "error configuring folly" >&2
+    tail -n 100 CMakeFiles/CMakeError.log >&2
+    exit 1
+fi
 make -j4
 make install
 touch "$INSTALL_MARKER_FILE"