bash-completion not working on core18-base classic snap

[Alberto Donato]

On my "sshoot" snap (sudo snap install sshoot --edge --classic), tab-completion with bash is currently not working.

I've followed steps on https://forum.snapcraft.io/t/debugging-tab-completion/4198 to debug, and I get no failure at any of the steps.

In step 4, when I run the complete command I get the following:

$ snap run --command=complete sshoot 9 9 7 1 " " 'sshoot ' sshoot ""
default

<output ends here>

instead of getting possible completions.

If I run commands in step 5 and manually load completion from a shell in the snap, it works.

note that "core" needs to be installed in addition to "core18" before installing this snap because of https://github.com/snapcore/core18/issues/89

[John Lenton (chipaca)]

So, you're hitting two or three separate bugs. The extra one is if you try this on snapd and hit the ld-so absolute symlink one :)

Getting no completion if core isn't installed is fixed by https://github.com/snapcore/snapd/pull/6126

which you know can be worked around by ... installing core :-)

Getting no completion with core installed is fixed by
https://github.com/snapcore/snapd/pull/6129

we've gone over how to work around the second one on IRC, but it's: tweak your completion script to not have the function depend on $1 (I'd recommend you not call python to generate the completion script every time it's invoked, in any case).

[Zygmunt Krynicki (zyga)]

John, what is the status of this issue?

 * There is https://github.com/snapcore/core18/issues/89 which is currently open
 * The two pull requests referenced above are both merged
   * https://github.com/snapcore/snapd/pull/6126
   * https://github.com/snapcore/snapd/pull/6129
 * A casual examination of a core18 system shows that we don't have completion at all
   bash -<tab,tab> doesn't expand like it does on core16

[Zygmunt Krynicki (zyga)]

/me realises the issue talks about core18-based classically confined snap. Not strictly about a snap that runs on core18.

[Ratchanan Srirattanamet (peat-new)]

This problem seems to also happen on strictly-confined snap (lxd). And I guess I've found the issue.

https://github.com/snapcore/snapd/blob/4405f25a553d31876bfe5346948b9b8f0e2b67d4/data/completion/bash/complete.sh#L117

This line seems to hardcode the name of "core" snap in it.

[Ian Johnson (anonymouse67)]

I can not reproduce the issue for either lxd or sshoot on my Groovy desktop, I get tab completion results for both snaps. Can folks confirm if this is still an issue for them and specify what system (`snap version`) and what snaps you have installed (`snap list`) if you can reproduce the issue?

[Alberto Donato (ack)]

It's working for me as well (on both snaps) on Groovy.

[Ian Johnson (anonymouse67)]

Thanks for confirmation. We still have the known issue about completion not working on Ubuntu Core 18, but I think this bug is resolved for classic Ubuntu installs with bash.