In a stack that doesn't have the pack user pack build fails to export

[dsyer]

*** EXPORTING:
Step 1/3 : FROM cfbuildpacks/cflinuxfs3-cnb-experimental:run
---> 2b15b1dbf8f9
Step 2/3 : ADD --chown=pack:pack /workspace/app /workspace/app
Error: image build: unable to convert uid/gid chown string to host mapping: can't find uid for user pack: no such user: pack
Usage:

[ekcasey]

I am going to change it to use the $PACK_USER_ID and $PACK_USER_GID env vars to determine the user and group. Those variables will need to be set on the stack images if they aren't already.

[nebhale]

@ekcasey You should open an issue in the stack specification for this and link it back to here.

[dsyer]

There is a org.cloudfoundry.stacks.cflinuxfs3 stack that I have been trying to use and it doesn't have those env vars (I have to add them using a manual docker build - thanks @dgodd for the tip). Whoever is maintaining that should get the message as well (I have no idea).

[ekcasey]

buildpacks/spec#16

[sclevine]

Whoever is maintaining that should get the message as well (I have no idea).

That stack contains unfinished development images maintained by the CF buildpacks team. Follow https://www.pivotaltracker.com/story/show/160291184 for updates.

[dsyer]

I can't make comments on that tracker. Can someone ask then to add yj (seems like it is in packs/build)? Maybe it has to have a debian package?

[sclevine]

I can prioritize a story to get yj added to it.

I'm worried about the CNB version of cflinuxfs3 diverging from the CF production version of cflinuxfs3, but I think it's reasonable to include it for simple shell script CNBs, given the TOML parsing requirements.