Re: [PATCH] devshell: introduce intercepts as per native / nativesdk

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Wed, 2022-04-20 at 11:11 -0400, Paul Gortmaker wrote:
> In a devshell, recent versions of git will complain if the repo is owned
> by someone other than the current UID - consider this example:
> 
>  ------
>   bitbake -c devshell linux-yocto
> 
>   [...]
> 
>   kernel-source#git branch
>   fatal: unsafe repository ('/home/paul/poky/build-qemuarm64/tmp/work-shared/qemuarm64/kernel-source' is owned by someone else)
>   To add an exception for this directory, call:
> 
>         git config --global --add safe.directory /home/paul/poky/build-qemuarm64/tmp/work-shared/qemuarm64/kernel-source
>   kernel-source#
>  ------
> 
> Of course the devshell has UID zero and the "real" UID is for "paul" in
> this case.  And so recent git versions complain.
> 
> As the whole purpose of the devshell is to invoke a shell where development
> can take place, having a non-functional git is clearly unacceptable.
> 
> Richard suggested we could use PSEUDO_UNLOAD=1 to evade this issue, and I
> suggested we probably will see other similar instances like this and should
> make use of PATH to intercept via devshell wrappers - conveniently we already
> have examples of this.
> 
> Here, we copy the existing "ar" example and tune it to the needs of git to
> combine Richard's suggestion and mine.
> 
> As such we now also can store commit logs and use send-email with our user
> specific settings, instead of "root", so in additon to fixing basic
> commands like "git branch" it should also increase general usefulness.
> 
> Cc: Richard Purdie <richard.purdie@linuxfoundation.org>
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> 
> diff --git a/meta/classes/devshell.bbclass b/meta/classes/devshell.bbclass
> index 62dc958d9a4a..7ac134e0950f 100644
> --- a/meta/classes/devshell.bbclass
> +++ b/meta/classes/devshell.bbclass
> @@ -2,6 +2,8 @@ inherit terminal
>  
>  DEVSHELL = "${SHELL}"
>  
> +PATH:prepend = "${COREBASE}/scripts/devshell-intercept:"
> +

I just realised, we can't do that! It would apply globally and mean builds
change behaviour depending on whether devshell is inherited or not. It also
means all git calls run through the wrapper, not just devshell ones.

I've also realised we have a bigger problem since some software is running git
to get the version during do_install.

My proposal is to change scripts/devshell-intercept to scripts/git-intercept,
make the PATH change in the do_devshell function below but also add something
like:

PATH:prepend:task-do_install = "${COREBASE}/scripts/git-intercept:"

in common code.

Since this hasn't merged yet, I can tweak the patch if that works for you (or
you can)?

Cheers,

Richard