./tools/install_builder_prerequisites.sh should describe next steps on errors

I tried to run the ./tools/install_builder_prerequisites.sh script today. This appeared to fail at the end with the following message:

$ ./tools/install_builder_prerequisites.sh 
Install (or update) [pkg:/package/pkg build-essential library/postgresql-13 pkg-config library/libxmlsec1 pkg:/ooce/developer/clang-120]? (y/n): y
           Packages to install:        12
           Mediators to change:         2
            Services to change:         1
     Estimated space available: 915.19 GB
Estimated space to be consumed:   1.31 GB
       Create boot environment:        No
Create backup boot environment:        No
          Rebuild boot archive:        No
... (snipping most of this)
+ curl --silent --show-error --fail --location --output out/downloads/ddm-admin-21fd8236c23dc38fea5d1e4c8196be685c251da2.json https://buildomat.eng.oxide.computer/public/file/oxidecomputer/maghemite/openapi/21fd8236c23dc38fea5d1e4c8196be685c251da2/ddm-admin.json
++ do_sha256sum out/downloads/ddm-admin-21fd8236c23dc38fea5d1e4c8196be685c251da2.json
++ case "$OSTYPE" in
++ SHA=sha256sum
++ sha256sum
++ awk '{print $1}'
+ calculated_sha2=c0be706f0e669b57644aa633145f9a10c53523e884cf9b814d34e9432a24091c
+ [[ c0be706f0e669b57644aa633145f9a10c53523e884cf9b814d34e9432a24091c != \c\0\b\e\7\0\6\f\0\e\6\6\9\b\5\7\6\4\4\a\a\6\3\3\1\4\5\f\9\a\1\0\c\5\3\5\2\3\e\8\8\4\c\f\9\b\8\1\4\d\3\4\e\9\4\3\2\a\2\4\0\9\1\c ]]
ERROR: cockroach seems installed, but was not found in PATH. Please add it.
cockroach should have been installed to '/home/rm/omicron/out/cockroachdb/bin'
ERROR: clickhouse seems installed, but was not found in PATH. Please add it.
clickhouse should have been installed to '/home/rm/omicron/out/clickhouse'

I assume that this error is expected because it's hard to set the PATH to something that doesn't exist and isn't mentioned in the getting started guide at https://github.com/oxidecomputer/omicron/blob/main/docs/how-to-run-simulated.adoc. The same applies to the non-simulated guide. What's not clear is what to do next. In particular, here were questions that I had:

• Do I need to set the env vars and re-run the the ./tools/install_builder_prerequisites.sh script?
• What operations do these environment variables need to be set for?

If this is expected, I think it'd help to actually just say this is OK and is a warning perhaps? I lost the exit status of the program accidentally in the shell, but seeing the ERROR leading text led me to believe that this had failed and I had done something wrong. It may also help to actually mention these env vars and when they are/aren't needed to the getting started guide. I'm not going to be permanently modifying PATH for this.