Unbound variable error for helm cli

[pratik136]

Describe the bug

Pressing tab when using the helm cli cancels the command with the message "BASH_COMP_DEBUG_FILE: unbound variable"

To reproduce

1. Install the helm cli
2. Type 'helm i tab'
3. See problem

Expected behavior

Ideally we would expect the 'i' to expand to 'install'. Alternatively, the completion tab could simply be ignored.

Versions (please complete the following information)

• Operating system name/distribution and version: Alpine Linux v3.14 running as a container
• bash version, echo "$BASH_VERSION": 5.1.4(1)-release
• bash-completion version, (IFS=.; echo "${BASH_COMPLETION_VERSINFO[*]}"): 2.11

Debug trace

bash-completions-error-debug-dump.txt

[akinomyoga]

I cannot find any string BASH_COMP_DEBUG_FILE in the bash-completion repository. This is the issue in the completion scripts generated by helm. The completion script of helm seems to be generated by the command helm completion bash. The problematic completion code seems to be emitted by GenBashCompletion called at cmd/helm/completion.go L132 (helm/helm). The function GenBashCompletion seems to be defined in a golang library, spf13/cobra. The culprit is bash_completions.go L27 (spf13/cobra).

Since this is the problem of the completion script generator spf13/cobra, there are so many affected scripts.

[scop]

Yeah, this is a long standing issue with cobra, and PR's such as spf13/cobra#1321 have unfortunately been stuck waiting for a longish time. But I'm afraid there's nothing we can do about it here, a workaround is to turn nounset mode off.