Homebrew: libexec is ignored

[AkihiroSuda]

The following PR updates the lima formula to install libexec:

• lima: install libexec Homebrew/homebrew-core#252989

$ limactl -v
limactl version 2.0.0-rc.1

$ which limactl
/opt/homebrew/bin/limactl

$ ls /opt/homebrew/opt/lima/libexec/lima/
lima-driver-krunkit* limactl-mcp*

However, the installed libexec components are not recognized by lima

$ limactl mcp
FATA[0000] unknown command "mcp" for "limactl" 

$ limactl start --vm-type krunkit
? Creating an instance "default" Proceed with the current configuration
FATA[0002] failed to resolve vm for "/Users/suda/.lima/default/lima.yaml": vmType "krunkit" is not a registered driver

[AkihiroSuda]

/opt/homebrew/bin/limactl doesn't work, but /opt/homebrew/opt/lima/bin/limactl seems to work.

A similar issue happened when splitting additional-guestagents in v1.1.

[AkihiroSuda]

This is complicated because /opt/homebrew/libexec does not exist, while /opt/homebrew/share exists

[jandubois]

How do you get a test-install of the binaries from your formula? I can give it a try tomorrow.

We determine the PREFIX by looking for the guest agent binaries relative to the location of limactl, or the location where it points to, if it is a symlink.

Then we expect the libexec directory to exist 2 levels up relative to that directory.

There are too many configurations possible with Homebrew and Nix managing packages in different ways, and the code trying to do the right thing for all of them.

[afbjorklund]

You might need to add /opt/homebrew/lib/lima to the search directories as well, otherwise it will not be possible for other formulas to install drivers.. The libexec is private to the lima installation, and not accessible in the prefix.

The workaround (for now) is to install the other drivers in the PATH... (like /opt/homebrew/bin)

NOTE: the prefix is configurable, so it might need an environment variable

Using the unresolved path would also work, though

[AkihiroSuda]

/opt/homebrew/lib/lima

This doesn't seem relevant to libexec

[afbjorklund]

/opt/homebrew/lib/lima

This doesn't seem relevant to libexec

The "lib" is shared (symlinked), but "libexec" is not (private).

But we can use "bin"

[AkihiroSuda]

Can we ask Homebrew maintainers to create the shared /opt/homebrew/libexec?
Was it already asked by somebody and rejected?

[afbjorklund]

It is a design choice (and FHS)

Should be in FAQ, can dig

https://docs.brew.sh/Formula-Cookbook

Note that in the context of Homebrew, libexec is reserved for private use by the formula and therefore is not symlinked into HOMEBREW_PREFIX.

[afbjorklund]

Actually using "bin" does not work OOTB either, have to configure the environment variable.

DEBU[0001] Discovering external drivers in [/opt/homebrew/Cellar/lima/2.0.1/libexec/lima] 
FATA[0001] failed to resolve vm for "/Users/afb/.lima/ac/lima.yaml": vmType "ac" is not a registered driver 

So something like export LIMA_DRIVERS_PATH=$HOMEBREW_PREFIX/bin, since libexec is private.

DEBU[0000] Discovering external drivers in [/opt/homebrew/Cellar/lima/2.0.1/libexec/lima] 
DEBU[0000] Pre-configured driver action completed successfully for "/opt/homebrew/bin/lima-driver-ac"