ci/travis: rename $BUILD_NVIM_DEPS to $CACHE_ENABLE

.travis.yml

@@ -4,8 +4,8 @@ language: c
 
 env:
   global:
-    # To force rebuilding of third-party dependencies, set this to 'true'.
-    - BUILD_NVIM_DEPS=false
+    # Set "false" to force rebuild of third-party dependencies.
+    - CACHE_ENABLE=true
     # Build directory for Neovim.
     - BUILD_DIR="$TRAVIS_BUILD_DIR/build"
     # Build directory for third-party dependencies.
@@ -36,9 +36,7 @@ env:
     - UBSAN_OPTIONS="print_stacktrace=1 log_path=$LOG_DIR/ubsan"
     # Environment variables for Valgrind.
     - VALGRIND_LOG="$LOG_DIR/valgrind-%p.log"
-    # Cache marker for third-party dependencies cache.
-    # If this file exists, we know that the cache contains compiled
-    # dependencies and we can use it.
+    # If this file exists, the cache is valid (compile was successful).
     - CACHE_MARKER="$HOME/.cache/nvim-deps/.travis_cache_marker"
     # default target name for functional tests
     - FUNCTIONALTEST=functionaltest

ci/common/build.sh

@@ -20,14 +20,13 @@ build_deps() {
 
   rm -rf "${DEPS_BUILD_DIR}"
 
-  # If there is a valid cache and we're not forced to recompile,
-  # use cached third-party dependencies.
-  if test -f "${CACHE_MARKER}" && test "${BUILD_NVIM_DEPS}" != "true" ; then
+  # Use cached dependencies if $CACHE_MARKER exists.
+  if test -f "${CACHE_MARKER}" && ! test "${CACHE_ENABLE}" = "false" ; then
     local statcmd="stat -c '%y'"
     if test "${TRAVIS_OS_NAME}" = osx ; then
       statcmd="stat -f '%Sm'"
     fi
-    echo "Using third-party dependencies from Travis's cache (last updated: $(${statcmd} "${CACHE_MARKER}"))."
+    echo "Using third-party dependencies from Travis cache (last update: $(${statcmd} "${CACHE_MARKER}"))."
 
     mkdir -p "$(dirname "${DEPS_BUILD_DIR}")"
     mv "${HOME}/.cache/nvim-deps" "${DEPS_BUILD_DIR}"