Can't build caddy docker image

[leobeal]

What happened?

Hi everyone, and congrats Kévin on the php foundation support 👏

So, I am not able to build a Docker image with custom Caddy modules as per these docs

It was working correctly until few weeks ago, but with the newer base images (not sure exactly from which version) I get the attached error.

EDIT: I tried with different builder versions and dunglas/frankenphp:1.6.2-builder works as expected.. the issue is with the latest (as shown in the docs)

Tried to build without cache, cleared my go cache, and nothing seems to work. I also tried successfully to build caddy based on this docs so it does not seem environment related.

Thanks for your time,

Build Type

Custom (tell us more in the description)

Worker Mode

No

Operating System

macOS

CPU Architecture

Apple Silicon

PHP configuration

default - fails before I try to install any extension

Relevant log output

36.65 2025/06/23 21:35:37 [INFO] exec (timeout=0s): /usr/local/go/bin/go build -o /usr/local/bin/frankenphp -ldflags=-w -s -tags=nobadger,nomysql,nopgx 
37.25 /go/src/app/backoff.go:1:1: expected 'package', found 'EOF'
37.25 /go/src/app/caddy/admin.go:1:1: expected 'package', found 'EOF'
37.26 2025/06/23 21:35:38 [INFO] Cleaning up temporary folder: /tmp/buildenv_2025-06-23-2135.2372736541
37.26 2025/06/23 21:35:38 [FATAL] exit status 1
------
Dockerfile:10