further theta script cleanups for jenkins use

- fix bug in previous tmp dir settings
- auto generate repos.yaml to avoid polluting ~/.spack

perf-regression/theta/run-regression.sh

@@ -16,9 +16,9 @@ module load cce
 export CFLAGS="-O3"
 export CRAYPE_LINK_TYPE=dynamic
 
-SANDBOX=./mochi-regression-sandbox-$$
-PREFIX=./mochi-regression-install-$$
-JOBDIR=./mochi-regression-job-$$
+SANDBOX=$PWD/mochi-regression-sandbox-$$
+PREFIX=$PWD/mochi-regression-install-$$
+JOBDIR=$PWD/mochi-regression-job-$$
 
 # scratch area to clone and build things
 mkdir -p $SANDBOX
@@ -43,8 +43,14 @@ cd $SANDBOX/spack
 patch -p1 < ../spack-shell.patch
 export SPACK_SHELL=bash
 . $SANDBOX/spack/share/spack/setup-env.sh
+# put packages file in place in SPACK_ROOT to set our preferences for building
+# Mochi stack
 cp $SANDBOX/packages.yaml $SPACK_ROOT/etc/spack
-spack repo add $SANDBOX/sds-repo
+# set up repos file to point to sds-repo; we do this manually because 
+#    "spack repo add" will create files in ~/.spack, which is a bad idea in 
+#    CI environments
+echo "repos:" > $SPACK_ROOT/etc/spack/repos.yaml
+echo "- ${SANDBOX}/sds-repo" >> $SPACK_ROOT/etc/spack/repos.yaml
 spack uninstall -R -y argobots mercury libfabric  | true
 spack install ssg
 # deliberately repeat setup-env step after building modules to ensure