CI_WORKSPACE variable doesn't work with string substitution

[june128]

Component

server, agent

Describe the bug

Using the CI_WORKSPACE variable using string substitution in an entrypoint doesn't work. Other variables like e.g. CI do work.

Steps to reproduce

1. Define a workflow containing the following steps:

   - name: test-1
     image: debian
     entrypoint:
       - /bin/bash
       - -c
       - echo hello${CI}
   - name: test-2
     image: debian
     entrypoint:
       - /bin/bash
       - -c
       - echo hello${CI_WORKSPACE}

2. Run the workflow
3. Observe the output in the Web interface

Expected behavior

The output being:

• for test-1: hellowoodpecker
• for test-2: hello<FULLWORKSPACEPATH>

What's actually being output:

• for test-1: hellowoodpecker
• for test-2: hello

System Info

{"source":"https://github.com/woodpecker-ci/woodpecker","version":"2.7.0"}

Additional context

Woodpecker running on NixOS. Config available here.

Validations

• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Checked that the bug isn't fixed in the next version already [https://woodpecker-ci.org/faq#which-version-of-woodpecker-should-i-use]

[june128]

Okay, tested a bit more andCI_WORKSPACE just doesn't work with string substitution it seems.
Having the following commands in a CI step:

- echo "hi $CI_WORKSPACE $CI"
- echo "hi ${CI_WORKSPACE} ${CI}"

results in the following output:

+ echo "hi $CI_WORKSPACE $CI"
hi /base/src woodpecker
+ echo "hi  woodpecker"
hi  woodpecker

[6543]

Ah ... yes there are different env variables, some are already available while parsing, others on runntime.

Rather than a bug we should update the docs ...

[zc-devs]

#3983 (comment)

[june128]

@6543 Ye fair enough. I guess as with #3983 updating the docs would be a good idea and having this issue be considered a feature request then.