bug 1350093 - fix sccache configuration to handle changes in the format of TASKCLUSTER_WORKER_GROUP. r=froydnj

The TASKCLUSTER_WORKER_GROUP environment variable used to contain the full
AWS availability zone, but a recent docker-worker change changed it to
be simply the AWS region, which broke sccache in taskcluster because we
were using it as part of the S3 bucket name.

MozReview-Commit-ID: 1KsfWpB4PoY

--HG--
extra : rebase_source : bdc61f180bf079eb0ad2cdbbd25e3e3a0deb62e6

build/mozconfig.cache

@@ -49,7 +49,10 @@ if test -z "$bucket" -a -z "$SCCACHE_DISABLE" -a -z "$no_sccache" -a -z "$MOZ_PG
     # 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 "${TASKCLUSTER_WORKER_GROUP}"; then
-            availability_zone="${TASKCLUSTER_WORKER_GROUP}"
+            # 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"
         else
             # timeout after 1 second, and don't retry (failure indicates instance is not in ec2 or network issue)
             # availability_zone is of the form <region><letter> where region is e.g. us-west-2, and az is us-west-2a

taskcluster/scripts/builder/build-linux.sh

@@ -52,7 +52,7 @@ export LIBRARY_PATH=$LIBRARY_PATH:$WORKSPACE/src/obj-firefox:$WORKSPACE/src/gcc/
 
 if [[ -n ${USE_SCCACHE} ]]; then
     # Point sccache at the Taskcluster proxy for AWS credentials.
-    export AWS_IAM_CREDENTIALS_URL="http://taskcluster/auth/v1/aws/s3/read-write/taskcluster-level-${MOZ_SCM_LEVEL}-sccache-${TASKCLUSTER_WORKER_GROUP%?}/?format=iam-role-compat"
+    export AWS_IAM_CREDENTIALS_URL="http://taskcluster/auth/v1/aws/s3/read-write/taskcluster-level-${MOZ_SCM_LEVEL}-sccache-${TASKCLUSTER_WORKER_GROUP}/?format=iam-role-compat"
 fi
 
 # test required parameters are supplied