Streamline BUILD_THIS modifiers

Since currently not many people (except for obreitwi) are using the
build cache api, take the opportunity to streamline parameter names and
have all modifiers for `BUILD_THIS` start with `WITH`:
    * `WITH_CACHE_NAME` (renamed from `USE_CACHE_NAME`)
    * `WITHOUT_FAILED_CACHE` (renamed from `NO_FAILED_CACHE`)
    * `WITH_DEBUG`
    * `WITH_SPACK_CHANGE`

Change-Id: Ibecdd8e93516a8297373c7a0763b0d9827791dfe

.ci/validate_environment.sh

@@ -35,9 +35,9 @@ SOURCE_DIR="$(dirname "$(readlink -m "${BASH_SOURCE[0]}")")"
 source "${SOURCE_DIR}/commons.sh"
 
 # For testing changesets, see if user supplied a custom build cache with
-# `USE_CACHE_NAME=<name>`. If not, check if there is a saved build cache from a
+# `WITH_CACHE_NAME=<name>`. If not, check if there is a saved build cache from a
 # previous build of this changeset and use that as build cache. If the comment
-# contains `NO_FAILED_CACHE` we do nothing, i.e. we use the default cache.
+# contains `WITHOUT_FAILED_CACHE` we do nothing, i.e. we use the default cache.
 #
 # Also we check if the gerrit comment message contains a spack change with
 # which we should build specified via `WITH_SPACK_CHANGE=<change-id>`.
@@ -55,11 +55,11 @@ if [ "${CONTAINER_BUILD_TYPE}" = "testing" ] \
         set_debug_output_from_env
     fi
 
-    if ! grep -q "\bNO_FAILED_CACHE\b" "${tmpfile_comment}"; then
-        if grep -q "\bUSE_CACHE_NAME=" "${tmpfile_comment}"; then
+    if ! grep -q "\bWITHOUT_FAILED_CACHE\b" "${tmpfile_comment}"; then
+        if grep -q "\bWITH_CACHE_NAME=" "${tmpfile_comment}"; then
             # use specified cache
             BUILD_CACHE_NAME="$(sed -nE \
-                -e "s:.*\<USE_CACHE_NAME=(\S*)\>.*:\1:gp" \
+                -e "s:.*\<WITH_CACHE_NAME=(\S*)\>.*:\1:gp" \
                 "${tmpfile_comment}")"
             export BUILD_CACHE_NAME
         else

README.md

@@ -9,21 +9,21 @@ Visionary "containering"…
 Start a yashicki build with this change as toplevel.
 
 
-### `NO_FAILED_CACHE`
+### `WITHOUT_FAILED_CACHE`
 
 If a testing build fails, link all preserved packages and the current build
 cache to a new temporary build cache under `failed/c<num>p<num>_<num>`.
 
 Behaviour for testing builds triggered from gerrit:
-* Unless the user specifies `NO_FAILED_CACHE` in the gerrit commit,
+* Unless the user specifies `WITHOUT_FAILED_CACHE` in the gerrit commit,
   check if there is a failed build cache for this changeset that was
   created as described above and use the latest one as build cache for
   the current build.
-* The user can also supply `USE_CACHE_NAME=<name>` to specify a
+* The user can also supply `WITH_CACHE_NAME=<name>` to specify a
   different build cache to be used for this build.
 
 
-### `USE_CACHE_NAME=<name>`
+### `WITH_CACHE_NAME=<name>`
 
 Use `/home/vis_jenkins/build_caches/<name>` on `conviz` as buildcache instead
 of the default one. Can also be used for failed caches.