--- a/browser/config/mozconfigs/linux32/debug
+++ b/browser/config/mozconfigs/linux32/debug
@@ -15,9 +15,8 @@ export MOZ_TELEMETRY_REPORTING=1
 #Use ccache
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/linux32/devedition
+++ b/browser/config/mozconfigs/linux32/devedition
@@ -15,9 +15,8 @@ ac_add_options --enable-verify-mar
 # by 2 MBs.
 STRIP_FLAGS="--strip-debug"
 
 ac_add_options --with-branding=browser/branding/aurora
 
 mk_add_options MOZ_PGO=1
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/linux32/l10n-mozconfig
+++ b/browser/config/mozconfigs/linux32/l10n-mozconfig
@@ -1,10 +1,8 @@
-no_sccache=1
-
 ac_add_options --with-l10n-base=../../l10n
 ac_add_options --enable-update-channel=${MOZ_UPDATE_CHANNEL}
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.no-compile"
 
 if test `uname -m` = "x86_64"; then
   ac_add_options --target=i686-pc-linux

--- a/browser/config/mozconfigs/linux32/l10n-mozconfig-devedition
+++ b/browser/config/mozconfigs/linux32/l10n-mozconfig-devedition
@@ -1,10 +1,8 @@
-no_sccache=1
-
 ac_add_options --with-l10n-base=../../l10n
 ac_add_options --enable-update-channel=${MOZ_UPDATE_CHANNEL}
 ac_add_options --with-branding=browser/branding/aurora
 
 . "$topsrcdir/build/mozconfig.no-compile"
 
 if test `uname -m` = "x86_64"; then
   ac_add_options --target=i686-pc-linux

--- a/browser/config/mozconfigs/linux32/nightly
+++ b/browser/config/mozconfigs/linux32/nightly
@@ -6,9 +6,8 @@ ac_add_options --enable-verify-mar
 # This will overwrite the default of stripping everything and keep the symbol table.
 # This is useful for profiling and debugging and only increases the package size
 # by 2 MBs.
 STRIP_FLAGS="--strip-debug"
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/linux64/debug
+++ b/browser/config/mozconfigs/linux64/debug
@@ -15,9 +15,8 @@ export MOZILLA_OFFICIAL=1
 export MOZ_TELEMETRY_REPORTING=1
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/linux64/debug-static-analysis-clang
+++ b/browser/config/mozconfigs/linux64/debug-static-analysis-clang
@@ -19,9 +19,8 @@ export CXX="$topsrcdir/clang/bin/clang++
 ac_add_options --enable-clang-plugin
 
 . "$topsrcdir/build/unix/mozconfig.stdcxx"
 
 export PKG_CONFIG_LIBDIR=/usr/lib64/pkgconfig:/usr/share/pkgconfig
 . $topsrcdir/build/unix/mozconfig.gtk
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/linux64/devedition
+++ b/browser/config/mozconfigs/linux64/devedition
@@ -15,9 +15,8 @@ ac_add_options --enable-verify-mar
 # by 2 MBs.
 STRIP_FLAGS="--strip-debug"
 
 ac_add_options --with-branding=browser/branding/aurora
 
 mk_add_options MOZ_PGO=1
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/linux64/l10n-mozconfig
+++ b/browser/config/mozconfigs/linux64/l10n-mozconfig
@@ -1,10 +1,8 @@
-no_sccache=1
-
 ac_add_options --with-l10n-base=../../l10n
 ac_add_options --enable-update-channel=${MOZ_UPDATE_CHANNEL}
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.no-compile"
 
 export MOZILLA_OFFICIAL=1
 

--- a/browser/config/mozconfigs/linux64/l10n-mozconfig-devedition
+++ b/browser/config/mozconfigs/linux64/l10n-mozconfig-devedition
@@ -1,10 +1,8 @@
-no_sccache=1
-
 ac_add_options --with-l10n-base=../../l10n
 ac_add_options --enable-update-channel=${MOZ_UPDATE_CHANNEL}
 ac_add_options --with-branding=browser/branding/aurora
 
 . "$topsrcdir/build/mozconfig.no-compile"
 
 export MOZILLA_OFFICIAL=1
 

--- a/browser/config/mozconfigs/linux64/nightly
+++ b/browser/config/mozconfigs/linux64/nightly
@@ -6,9 +6,8 @@ ac_add_options --enable-verify-mar
 # This will overwrite the default of stripping everything and keep the symbol table.
 # This is useful for profiling and debugging and only increases the package size
 # by 2 MBs.
 STRIP_FLAGS="--strip-debug"
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/linux64/opt-static-analysis-clang
+++ b/browser/config/mozconfigs/linux64/opt-static-analysis-clang
@@ -18,9 +18,8 @@ CXX="$topsrcdir/clang/bin/clang++"
 ac_add_options --enable-clang-plugin
 
 . "$topsrcdir/build/unix/mozconfig.stdcxx"
 
 export PKG_CONFIG_LIBDIR=/usr/lib64/pkgconfig:/usr/share/pkgconfig
 . $topsrcdir/build/unix/mozconfig.gtk
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/macosx64/beta
+++ b/browser/config/mozconfigs/macosx64/beta
@@ -4,9 +4,8 @@ if [ -n "$ENABLE_RELEASE_PROMOTION" ]; t
 fi
 
 . "$topsrcdir/browser/config/mozconfigs/macosx64/common-opt"
 
 ac_add_options --enable-official-branding
 ac_add_options --enable-verify-mar
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/macosx64/debug
+++ b/browser/config/mozconfigs/macosx64/debug
@@ -15,9 +15,8 @@ ac_add_options --with-macbundlename-pref
 fi
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/macosx64/debug-static-analysis
+++ b/browser/config/mozconfigs/macosx64/debug-static-analysis
@@ -5,9 +5,8 @@ MOZ_AUTOMATION_L10N_CHECK=0
 . $topsrcdir/build/macosx/mozconfig.common
 
 ac_add_options --enable-debug
 ac_add_options --enable-dmd
 
 ac_add_options --enable-clang-plugin
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/macosx64/devedition
+++ b/browser/config/mozconfigs/macosx64/devedition
@@ -20,9 +20,8 @@ fi
 
 if test "${MOZ_UPDATE_CHANNEL}" = "nightly"; then
 ac_add_options --with-macbundlename-prefix=Firefox
 fi
 
 ac_add_options --with-branding=browser/branding/aurora
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/macosx64/nightly
+++ b/browser/config/mozconfigs/macosx64/nightly
@@ -12,9 +12,8 @@ fi
 
 if test "${MOZ_UPDATE_CHANNEL}" = "nightly"; then
 ac_add_options --with-macbundlename-prefix=Firefox
 fi
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/macosx64/opt-static-analysis
+++ b/browser/config/mozconfigs/macosx64/opt-static-analysis
@@ -6,10 +6,9 @@ MOZ_AUTOMATION_L10N_CHECK=0
 
 ac_add_options --disable-debug
 ac_add_options --enable-optimize
 ac_add_options --enable-dmd
 
 ac_add_options --enable-clang-plugin
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"
 

--- a/browser/config/mozconfigs/macosx64/release
+++ b/browser/config/mozconfigs/macosx64/release
@@ -11,9 +11,8 @@ fi
 ac_add_options --enable-official-branding
 ac_add_options --enable-verify-mar
 
 # safeguard against someone forgetting to re-set EARLY_BETA_OR_EARLIER in
 # defines.sh during the beta cycle
 export BUILDING_RELEASE=1
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/whitelist
+++ b/browser/config/mozconfigs/whitelist
@@ -21,56 +21,51 @@ for platform in ['linux32', 'linux64', '
     ]
 
 whitelist['nightly']['linux32'] += [
     'CXX=$REAL_CXX',
     'CXX="ccache $REAL_CXX"',
     'CC="ccache $REAL_CC"',
     'mk_add_options PROFILE_GEN_SCRIPT=@TOPSRCDIR@/build/profile_pageloader.pl',
     'ac_add_options --with-ccache=/usr/bin/ccache',
-    '. "$topsrcdir/build/mozconfig.cache"',
     'export MOZILLA_OFFICIAL=1',
     'export MOZ_TELEMETRY_REPORTING=1',
     "mk_add_options PROFILE_GEN_SCRIPT='$(PYTHON) @MOZ_OBJDIR@/_profile/pgo/profileserver.py 10'",
     'STRIP_FLAGS="--strip-debug"',
 ]
 
 whitelist['nightly']['linux64'] += [
     'export MOZILLA_OFFICIAL=1',
     'export MOZ_TELEMETRY_REPORTING=1',
     "mk_add_options PROFILE_GEN_SCRIPT='$(PYTHON) @MOZ_OBJDIR@/_profile/pgo/profileserver.py 10'",
     'STRIP_FLAGS="--strip-debug"',
     'ac_add_options --with-ccache=/usr/bin/ccache',
-    '. "$topsrcdir/build/mozconfig.cache"',
 ]
 
 whitelist['nightly']['macosx64'] += [
     'if test "${MOZ_UPDATE_CHANNEL}" = "nightly"; then',
     'ac_add_options --with-macbundlename-prefix=Firefox',
     'fi',
     'mk_add_options MOZ_MAKE_FLAGS="-j12"',
     'ac_add_options --with-ccache',
-    '. "$topsrcdir/build/mozconfig.cache"',
     'ac_add_options --disable-install-strip',
     'ac_add_options --enable-instruments',
     'ac_add_options --enable-dtrace',
     'if test `uname -s` != Linux; then',
 ]
 
 whitelist['nightly']['win32'] += [
     '. $topsrcdir/configs/mozilla2/win32/include/choose-make-flags',
     'mk_add_options MOZ_MAKE_FLAGS=-j1',
-    '. "$topsrcdir/build/mozconfig.cache"',
     'if test "$IS_NIGHTLY" != ""; then',
     'ac_add_options --disable-auto-deps',
     'fi',
 ]
 whitelist['nightly']['win64'] += [
     '. "$topsrcdir/browser/config/mozconfigs/win64/common-win64"',
-    '. "$topsrcdir/build/mozconfig.cache"',
 ]
 
 for platform in all_platforms:
     whitelist['release'][platform] = [
         'ac_add_options --enable-update-channel=release',
         'ac_add_options --enable-official-branding',
         'mk_add_options MOZ_MAKE_FLAGS="-j4"',
         'export BUILDING_RELEASE=1',

--- a/browser/config/mozconfigs/win32/debug
+++ b/browser/config/mozconfigs/win32/debug
@@ -18,9 +18,8 @@ export MOZ_TELEMETRY_REPORTING=1
 . $topsrcdir/build/win32/mozconfig.vs-latest
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/win32/devedition
+++ b/browser/config/mozconfigs/win32/devedition
@@ -11,9 +11,8 @@ MOZ_REQUIRE_SIGNING=0
 
 ac_add_options --enable-verify-mar
 
 ac_add_options --with-branding=browser/branding/aurora
 
 mk_add_options MOZ_PGO=1
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/win32/nightly
+++ b/browser/config/mozconfigs/win32/nightly
@@ -2,9 +2,8 @@
 . "$topsrcdir/browser/config/mozconfigs/win32/common-opt"
 
 ac_add_options --enable-profiling
 ac_add_options --enable-verify-mar
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/win64/debug
+++ b/browser/config/mozconfigs/win64/debug
@@ -21,9 +21,8 @@ export MOZ_TELEMETRY_REPORTING=1
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . $topsrcdir/build/win64/mozconfig.vs-latest
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/win64/devedition
+++ b/browser/config/mozconfigs/win64/devedition
@@ -12,9 +12,8 @@ MOZ_REQUIRE_SIGNING=0
 
 ac_add_options --enable-verify-mar
 
 ac_add_options --with-branding=browser/branding/aurora
 
 mk_add_options MOZ_PGO=1
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/win64/nightly
+++ b/browser/config/mozconfigs/win64/nightly
@@ -3,9 +3,8 @@
 . "$topsrcdir/browser/config/mozconfigs/win64/common-opt"
 
 ac_add_options --enable-profiling
 ac_add_options --enable-verify-mar
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"

--- a/build/mozconfig.cache
+++ b/build/mozconfig.cache
@@ -9,17 +9,17 @@ if test -z "$bucket" -a -z "$NO_CACHE"; 
 
 # buildbot (or builders that use buildprops.json):
 if [ -f $topsrcdir/../buildprops.json ]; then
 read branch platform master <<EOF
 $(python2.7 -c 'import json; p = json.loads(open("'"$topsrcdir"'/../buildprops.json").read())["properties"]; print p["branch"], p["platform"], p["master"]' 2> /dev/null)
 EOF
 
 bucket=
-if test -z "$SCCACHE_DISABLE" -a -z "$no_sccache" -a -z "$MOZ_PGO_IS_SET" -a -z "$MOZ_PGO"; then
+if test -z "$SCCACHE_DISABLE" -a -z "$MOZ_PGO_IS_SET" -a -z "$MOZ_PGO"; then
     case "${branch}" in
     try)
         case "${master}" in
         *scl1.mozilla.com*|*.scl3.mozilla.com*)
             bucket=mozilla-releng-s3-cache-us-west-1-try
             ;;
         *use1.mozilla.com*)
             bucket=mozilla-releng-s3-cache-us-east-1-try
@@ -39,17 +39,17 @@ if test -z "$SCCACHE_DISABLE" -a -z "$no
             ;;
         esac
         ;;
     esac
 fi
 fi
 
 # builds where buildprops didn't have the data (eg: taskcluster or non-buildbot) and without sccache disabled:
-if test -z "$bucket" -a -z "$SCCACHE_DISABLE" -a -z "$no_sccache" -a -z "$MOZ_PGO_IS_SET" -a -z "$MOZ_PGO"; then
+if test -z "$bucket" -a -z "$SCCACHE_DISABLE" -a -z "$MOZ_PGO_IS_SET" -a -z "$MOZ_PGO"; then
 
     # prevent rerun if az is set, or wget is not available
     if test -z "$availability_zone" -a -x "$(command -v wget)"; then
         if test -n "${TASKCLUSTER_WORKER_GROUP}"; then
             # TASKCLUSTER_WORKER_GROUP is just the region now, so
             # stick an extra character on to make the already-convoluted logic
             # here simpler.
             availability_zone="${TASKCLUSTER_WORKER_GROUP}x"
@@ -103,26 +103,26 @@ if test -z "$platform"; then
         ;;
     esac
 fi
 
 if test -z "$bucket"; then
     case "$platform" in
     win*) : ;;
     *)
-        ac_add_options --with-ccache
+        export CCACHE=ccache
     esac
 else
     mk_add_options "export SCCACHE_BUCKET=$bucket"
     case "$master" in
     *us[ew][12].mozilla.com*|*euc1.mozilla.com*)
         mk_add_options "export SCCACHE_NAMESERVER=169.254.169.253"
         ;;
     esac
-    ac_add_options "--with-ccache=$topsrcdir/sccache2/sccache${suffix}"
+    export CCACHE="$topsrcdir/sccache2/sccache${suffix}"
     export SCCACHE_VERBOSE_STATS=1
     mk_add_options MOZ_PREFLIGHT_ALL+=build/sccache.mk
     mk_add_options MOZ_POSTFLIGHT_ALL+=build/sccache.mk
     mk_add_options "UPLOAD_EXTRA_FILES+=sccache.log.gz"
     case "$platform" in
     win*)
         # sccache supports a special flag to create depfiles.
         #TODO: bug 1318370 - move this all into toolchain.configure

--- a/build/mozconfig.common
+++ b/build/mozconfig.common
@@ -18,8 +18,9 @@ ac_add_options --enable-crashreporter
 MOZ_ADDON_SIGNING=${MOZ_ADDON_SIGNING-1}
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_SIGNING=${MOZ_REQUIRE_SIGNING-0}
 
 ac_add_options --enable-js-shell
 
 . "$topsrcdir/build/mozconfig.automation"
 . "$topsrcdir/build/mozconfig.rust"
+. "$topsrcdir/build/mozconfig.cache"

--- a/build/mozconfig.no-compile
+++ b/build/mozconfig.no-compile
@@ -1,10 +1,15 @@
 ac_add_options --disable-compile-environment
 
+# In case mozconfig.cache was already included
+unset CCACHE
+# In case it wasn't
+NO_CACHE=1
+
 # Override any toolchain defines we've inherited from other mozconfigs.
 unset CC
 unset CXX
 unset HOST_CC
 unset HOST_CXX
 unset RUSTC
 unset CARGO
 unset MAKECAB

--- a/mobile/android/config/mozconfigs/common
+++ b/mobile/android/config/mozconfigs/common
@@ -78,17 +78,16 @@ else
 fi
 
 export SOCORRO_SYMBOL_UPLOAD_TOKEN_FILE=/builds/crash-stats-api.token
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 # Use ccache
-. "$topsrcdir/build/mozconfig.cache"
 
 HOST_CC="$topsrcdir/gcc/bin/gcc"
 HOST_CXX="$topsrcdir/gcc/bin/g++"
 
 . "$topsrcdir/build/unix/mozconfig.stdcxx"
 
 # Use libc++ as our C++ standard library
 ac_add_options --with-android-cxx-stl=libc++

--- a/mobile/android/config/mozconfigs/common.override
+++ b/mobile/android/config/mozconfigs/common.override
@@ -3,9 +3,8 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 # This file is included at the bottom of all native android mozconfigs
 #
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_SIGNING=0
 
 . "$topsrcdir/build/mozconfig.common.override"
-. "$topsrcdir/build/mozconfig.cache"