new file mode 100644
--- /dev/null
+++ b/build/mozconfig.comm-sccache
@@ -0,0 +1,8 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Must be included before M-C:build/mozconfig.cache
+if test -z "$aws_prefix" -a -z "$bucket" -a -z "$SCCACHE_DISABLE"; then
+  aws_prefix="comm-central"
+fi

deleted file mode 100644
--- a/build/mozconfig.sccache
+++ /dev/null
@@ -1,59 +0,0 @@
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-# Used in mail/config/mozconfigs by various mozconfigs.
-
-# Setup for build cache
-
-# Avoid duplication if the file happens to be included twice.
-if test -z "$NO_CACHE" -a -z "$SCCACHE_DISABLE"; then
-
-# ${region} is set by m-c's build/mozconfig.cache
-if test -n "$region"; then
-    # set S3 bucket according to tree (level)
-    case "${COMM_HEAD_REPOSITORY}" in
-    *hg.mozilla.org/try-comm-central*)
-	bucket=comm-central-level-1-sccache-${region}
-	;;
-    *hg.mozilla.org/comm-central*)
-	bucket=comm-central-level-3-sccache-${region}
-	;;
-    esac
-fi
-
-if test -n "$bucket"; then
-    mk_add_options "export SCCACHE_BUCKET=$bucket"
-    mk_add_options "export SCCACHE_NAMESERVER=169.254.169.253"
-    case "${SYSTEMROOT}" in
-    *Windows)
-        platform=win
-	;;
-    *)
-        mk_add_options "export AWS_IAM_CREDENTIALS_URL=http://taskcluster/auth/v1/aws/s3/read-write/${bucket}/?format=iam-role-compat"
-	;;
-    esac
-
-    export CCACHE="$MOZ_FETCHES_DIR/sccache/sccache${suffix}"
-    export SCCACHE_VERBOSE_STATS=1
-    mk_add_options "MOZBUILD_MANAGE_SCCACHE_DAEMON=$MOZ_FETCHES_DIR/sccache/sccache"
-    mk_add_options "UPLOAD_EXTRA_FILES+=sccache.log.gz"
-
-    case "$platform" in
-    win)
-        # sccache supports a special flag to create depfiles.
-        #TODO: bug 1318370 - move this all into toolchain.configure
-        export _DEPEND_CFLAGS='-deps$(MDDEPDIR)/$(@F).pp'
-        # Windows builds have a default wrapper that needs to be overridden
-        mk_add_options "export CC_WRAPPER="
-        mk_add_options "export CXX_WRAPPER="
-        # For now, sccache doesn't support separate PDBs so force debug info to be
-        # in object files.
-        mk_add_options "export COMPILE_PDB_FLAG="
-        mk_add_options "export HOST_PDB_FLAG="
-        mk_add_options "export MOZ_DEBUG_FLAGS=-Z7"
-        ;;
-    esac
-fi
-
-fi # NO_CACHE && SCCACHE_DISABLE

--- a/mail/config/mozconfigs/linux32/debug
+++ b/mail/config/mozconfigs/linux32/debug
@@ -1,10 +1,11 @@
 MOZ_AUTOMATION_L10N_CHECK=0
 
+. "$topsrcdir/comm/build/mozconfig.comm-sccache"
 . "$topsrcdir/build/unix/mozconfig.linux32"
 . "$topsrcdir/build/mozconfig.stylo"
 . "$topsrcdir/comm/mail/config/mozconfigs/common"
 
 ac_add_options --enable-debug
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
@@ -12,10 +13,8 @@ export MOZILLA_OFFICIAL=1
 # For NSS symbols
 export MOZ_DEBUG_SYMBOLS=1
 
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_ADDON_SIGNING=0
 
 # Package js shell
 export MOZ_PACKAGE_JSSHELL=1
-
-. "$topsrcdir/comm/build/mozconfig.sccache"

--- a/mail/config/mozconfigs/linux32/nightly
+++ b/mail/config/mozconfigs/linux32/nightly
@@ -1,8 +1,9 @@
+. "$topsrcdir/comm/build/mozconfig.comm-sccache"
 . "$topsrcdir/build/unix/mozconfig.linux32"
 . "$topsrcdir/build/mozconfig.stylo"
 . "$topsrcdir/comm/mail/config/mozconfigs/common"
 
 ac_add_options --enable-update-channel="${MOZ_UPDATE_CHANNEL}"
 ac_add_options --enable-profiling
 
 # Needed to enable breakpad in application.ini
@@ -15,10 +16,8 @@ export MOZ_DEBUG_SYMBOLS=1
 
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_ADDON_SIGNING=0
 
 # Package js shell
 export MOZ_PACKAGE_JSSHELL=1
 
 mk_add_options "export SOCORRO_SYMBOL_UPLOAD_TOKEN_FILE=/builds/crash-stats-api.token"
-
-. "$topsrcdir/comm/build/mozconfig.sccache"

--- a/mail/config/mozconfigs/linux64/debug
+++ b/mail/config/mozconfigs/linux64/debug
@@ -1,10 +1,11 @@
 MOZ_AUTOMATION_L10N_CHECK=0
 
+. "$topsrcdir/comm/build/mozconfig.comm-sccache"
 . "$topsrcdir/build/unix/mozconfig.linux"
 . "$topsrcdir/build/mozconfig.stylo"
 . "$topsrcdir/comm/mail/config/mozconfigs/common"
 
 ac_add_options --enable-debug
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
@@ -12,10 +13,8 @@ export MOZILLA_OFFICIAL=1
 # For NSS symbols
 export MOZ_DEBUG_SYMBOLS=1
 
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_ADDON_SIGNING=0
 
 # Package js shell
 export MOZ_PACKAGE_JSSHELL=1
-
-. "$topsrcdir/comm/build/mozconfig.sccache"

--- a/mail/config/mozconfigs/linux64/nightly
+++ b/mail/config/mozconfigs/linux64/nightly
@@ -1,8 +1,9 @@
+. "$topsrcdir/comm/build/mozconfig.comm-sccache"
 . "$topsrcdir/build/unix/mozconfig.linux"
 . "$topsrcdir/build/mozconfig.stylo"
 . "$topsrcdir/comm/mail/config/mozconfigs/common"
 
 ac_add_options --enable-update-channel="${MOZ_UPDATE_CHANNEL}"
 ac_add_options --enable-profiling
 
 # Needed to enable breakpad in application.ini
@@ -15,10 +16,8 @@ export MOZ_DEBUG_SYMBOLS=1
 
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_ADDON_SIGNING=0
 
 # Package js shell
 export MOZ_PACKAGE_JSSHELL=1
 
 mk_add_options "export SOCORRO_SYMBOL_UPLOAD_TOKEN_FILE=/builds/crash-stats-api.token"
-
-. "$topsrcdir/comm/build/mozconfig.sccache"

--- a/mail/config/mozconfigs/macosx64/debug
+++ b/mail/config/mozconfigs/macosx64/debug
@@ -1,8 +1,9 @@
+. "$topsrcdir/comm/build/mozconfig.comm-sccache"
 . "$topsrcdir/build/macosx/mozconfig.common"
 . "$topsrcdir/build/mozconfig.stylo"
 . "$topsrcdir/comm/mail/config/mozconfigs/common"
 
 ac_add_options --enable-debug
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
@@ -10,10 +11,8 @@ export MOZILLA_OFFICIAL=1
 # For NSS symbols
 export MOZ_DEBUG_SYMBOLS=1
 
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_ADDON_SIGNING=0
 
 # Package js shell
 export MOZ_PACKAGE_JSSHELL=1
-
-. "$topsrcdir/comm/build/mozconfig.sccache"

--- a/mail/config/mozconfigs/macosx64/nightly
+++ b/mail/config/mozconfigs/macosx64/nightly
@@ -1,8 +1,9 @@
+. "$topsrcdir/comm/build/mozconfig.comm-sccache"
 . "$topsrcdir/build/macosx/mozconfig.common"
 . "$topsrcdir/build/mozconfig.stylo"
 . "$topsrcdir/comm/mail/config/mozconfigs/common"
 
 ac_add_options --enable-update-channel="${MOZ_UPDATE_CHANNEL}"
 ac_add_options --disable-install-strip
 ac_add_options --enable-profiling
 
@@ -15,11 +16,9 @@ export MOZILLA_OFFICIAL=1
 export MOZ_TELEMETRY_REPORTING=1
 
 # Package js shell
 export MOZ_PACKAGE_JSSHELL=1
 
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_ADDON_SIGNING=0
 
-. "$topsrcdir/comm/build/mozconfig.sccache"
-
 mk_add_options "export SOCORRO_SYMBOL_UPLOAD_TOKEN_FILE=/builds/crash-stats-api.token"

--- a/mail/config/mozconfigs/win32/debug
+++ b/mail/config/mozconfigs/win32/debug
@@ -1,10 +1,11 @@
 MOZ_AUTOMATION_L10N_CHECK=0
 
+. "$topsrcdir/comm/build/mozconfig.comm-sccache"
 . "$topsrcdir/build/mozconfig.win-common"
 . "$topsrcdir/build/mozconfig.common"
 . "$topsrcdir/build/mozconfig.stylo"
 . "$topsrcdir/comm/mail/config/mozconfigs/common"
 
 ac_add_options --enable-debug
 
 # Needed to enable breakpad in application.ini
@@ -14,14 +15,12 @@ export MOZILLA_OFFICIAL=1
 export MOZ_DEBUG_SYMBOLS=1
 
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_ADDON_SIGNING=0
 
 # Package js shell
 export MOZ_PACKAGE_JSSHELL=1
 
-. "$topsrcdir/comm/build/mozconfig.sccache"
-
 . $topsrcdir/build/win32/mozconfig.vs-latest
 
 # Set up mapi includes (must be done after visual studio setup)
 export INCLUDE=$INCLUDE:$(cd "$TOOLTOOL_DIR" && pwd)/mapiheader

--- a/mail/config/mozconfigs/win32/nightly
+++ b/mail/config/mozconfigs/win32/nightly
@@ -1,8 +1,9 @@
+. "$topsrcdir/comm/build/mozconfig.comm-sccache"
 . "$topsrcdir/build/mozconfig.win-common"
 . "$topsrcdir/build/mozconfig.common"
 . "$topsrcdir/build/mozconfig.stylo"
 . "$topsrcdir/comm/mail/config/mozconfigs/common"
 
 ac_add_options --enable-update-channel="${MOZ_UPDATE_CHANNEL}"
 ac_add_options --enable-jemalloc
 ac_add_options --enable-profiling
@@ -16,16 +17,14 @@ export MOZ_TELEMETRY_REPORTING=1
 export MOZILLA_OFFICIAL=1
 
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_ADDON_SIGNING=0
 
 # Package js shell
 export MOZ_PACKAGE_JSSHELL=1
 
-. "$topsrcdir/comm/build/mozconfig.sccache"
-
 . $topsrcdir/build/win32/mozconfig.vs-latest
 
 # Set up mapi includes (must be done after visual studio setup)
 export INCLUDE=$INCLUDE:$(cd "$TOOLTOOL_DIR" && pwd)/mapiheader
 
 mk_add_options "export SOCORRO_SYMBOL_UPLOAD_TOKEN_FILE=c:/builds/crash-stats-api.token"

--- a/mail/config/mozconfigs/win64/debug
+++ b/mail/config/mozconfigs/win64/debug
@@ -1,10 +1,11 @@
 MOZ_AUTOMATION_L10N_CHECK=0
 
+. "$topsrcdir/comm/build/mozconfig.comm-sccache"
 . "$topsrcdir/build/mozconfig.win-common"
 . "$topsrcdir/build/mozconfig.common"
 . "$topsrcdir/build/mozconfig.stylo"
 . "$topsrcdir/comm/mail/config/mozconfigs/common"
 . "$topsrcdir/comm/mail/config/mozconfigs/win64/common-win64"
 
 ac_add_options --enable-debug
 if test -n "$USE_ARTIFACT"; then
@@ -15,16 +16,14 @@ fi
 export MOZILLA_OFFICIAL=1
 
 # Package js shell
 export MOZ_PACKAGE_JSSHELL=1
 
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_ADDON_SIGNING=0
 
-. "$topsrcdir/comm/build/mozconfig.sccache"
-
 if test -z "$USE_ARTIFACT"; then
 . $topsrcdir/build/win64/mozconfig.vs-latest
 
 # Set up mapi includes (must be done after visual studio setup)
 export INCLUDE=$INCLUDE:$(cd "$TOOLTOOL_DIR" && pwd)/mapiheader
 fi

--- a/mail/config/mozconfigs/win64/nightly
+++ b/mail/config/mozconfigs/win64/nightly
@@ -1,8 +1,9 @@
+. "$topsrcdir/comm/build/mozconfig.comm-sccache"
 . "$topsrcdir/build/mozconfig.win-common"
 . "$topsrcdir/build/mozconfig.common"
 . "$topsrcdir/build/mozconfig.stylo"
 . "$topsrcdir/comm/mail/config/mozconfigs/common"
 . "$topsrcdir/comm/mail/config/mozconfigs/win64/common-win64"
 
 ac_add_options --enable-update-channel="${MOZ_UPDATE_CHANNEL}"
 ac_add_options --enable-profiling
@@ -19,18 +20,16 @@ export MOZILLA_OFFICIAL=1
 export MOZ_TELEMETRY_REPORTING=1
 
 # Disable enforcing that add-ons are signed by the trusted root
 MOZ_REQUIRE_ADDON_SIGNING=0
 
 # Package js shell
 export MOZ_PACKAGE_JSSHELL=1
 
-. "$topsrcdir/comm/build/mozconfig.sccache"
-
 if test -z "$USE_ARTIFACT"; then
 . $topsrcdir/build/win64/mozconfig.vs-latest
 
 # Set up mapi includes (must be done after visual studio setup)
 export INCLUDE=$INCLUDE:$(cd "$TOOLTOOL_DIR" && pwd)/mapiheader
 
 mk_add_options "export SOCORRO_SYMBOL_UPLOAD_TOKEN_FILE=c:/builds/crash-stats-api.token"
 fi