Porting a new Golang app: go mod replace relative path

Good day,

I've been trying to create a new port and running into an issue.

Here is the port:
https://github.com/zachfi/personal-ports/blob/main/sysutils/alloy/Makefile

Here is the source of the issue:
https://github.com/zachfi/personal-ports/blob/main/sysutils/alloy/Makefile

When running `make makesum` to fetch all the dependencies, the local
reference fails with the following error message.

===> Fetching github.com/grafana/alloy dependencies go:
github.com/grafana/alloy/syntax@v0.1.0 (replaced by ./syntax): reading
syntax/go.mod: open
/usr/ports/distfiles/go/sysutils_alloy/grafana-alloy-v1.0.0_GH0/syntax/go.mod:
no such file or directory *** Error code 1

I've spoken with the authors, and they don't intend to keep a `vendor`
directory, nor do they intend to change the go mod replace line, so
I'm left wondering what my options are.

Is there a workaround for this?  Can we specify in the port that for a
specific module, to reference the module
github.com/grafana/alloy/syntax at the same version as the port?  Any
advice would be appreciated.

Cheers,

-- 
Zach