Make sure the Jenkins build script can patch itself

[Itms]

Case in point: building ​Phab:D1026 failed with

build/jenkins/build-patch.sh: 69: cd: can't cd to build/workspaces/gcc

meaning that the unpatched version of the script was still being executed. As far as I know a script that modifies itself keeps track of the current position in the file, so I have to assume the issue comes from the patched code being higher in the file (line 69) than the place where the patching happens (line 102).

I don't see an obvious way to fix this so I'm opening this ticket for tracking future improvements. Suggestions are welcome as well :-)

[leper]

As far as I know a script that modifies itself keeps track of the current position in the file

Bash tries somewhat hard to do that, however self-modifying code is just confusing and creating issues.

One could probably split that file into a few, then only load them when something is actually used. I wouldn't try to make the thing work when it is modified itself, that's just asking for pain.

The alternative would be to manually do the patching in such cases.

[Itms]

In 20635:

Use premake5 during automated testing, after a few weeks of use in production.
Refs #4846.

[Krinkle]

Is this still needed? I'm unable to find where the script tries to modify itself, or why that would be easier or needed to do something in CI.

[Itms]

Replying to Krinkle:

Is this still needed? I'm unable to find where the script tries to modify itself, or why that would be easier or needed to do something in CI.

No, I will close this as wontfix. What I am doing since I manage the CI is that I modify CI scripts manually and version them separately. By the way, I will soon update ​Phab:D1910 with the latest improvements to the CI.