Can't build with caddy/cache-handler on amd64

[cdaguerre]

The following Dockerfile can not be built for amd64 target arch, regardless of the underlying host machine.
It works fine for arm64.

FROM dunglas/frankenphp:latest-builder-php8.3-alpine AS builder

COPY --from=caddy:builder-alpine /usr/bin/xcaddy /usr/bin/xcaddy

ENV CGO_ENABLED=1 XCADDY_SETCAP=1
RUN xcaddy build \
    --output /usr/local/bin/frankenphp \
    --with github.com/dunglas/frankenphp=./ \
    --with github.com/dunglas/frankenphp/caddy=./caddy/ \
    --with github.com/dunglas/mercure/caddy \
    --with github.com/dunglas/vulcain/caddy \
    --with github.com/caddyserver/transform-encoder \
    --with github.com/darkweak/souin/plugins/caddy 	

95.61 2023/12/12 20:31:45 [INFO] exec (timeout=0s): /usr/local/go/bin/go build -o /usr/local/bin/frankenphp -ldflags -w -s -trimpath 
316.0 # caddy
316.0 /usr/local/go/pkg/tool/linux_amd64/link: running gcc failed: exit status 1
316.0 /usr/lib/gcc/x86_64-alpine-linux-musl/12.2.1/../../../../x86_64-alpine-linux-musl/bin/ld: /tmp/go-link-1036742013/000004.o: warning: relocation against `sapi_module' in read-only section `.text'
316.0 /usr/lib/gcc/x86_64-alpine-linux-musl/12.2.1/../../../../x86_64-alpine-linux-musl/bin/ld: /tmp/go-link-1036742013/000004.o: relocation R_X86_64_PC32 against symbol `stderr' can not be used when making a PDE object; recompile with -fPIE
316.0 /usr/lib/gcc/x86_64-alpine-linux-musl/12.2.1/../../../../x86_64-alpine-linux-musl/bin/ld: final link failed: bad value
316.0 collect2: error: ld returned 1 exit status

Things I've already tried :

• building without souin works
• building caddy with souin (without frankenphp) works (regardless of CGO)

Any help would be greatly appreciated!

[withinboredom]

Huh, yeah, that's a weird one. I tried setting:

CGO_CXXFLAGS=-fPIE CGO_CFLAGS=-fPIE CGO_LDFLAGS=-pie

and it didn't seem to make any difference (almost like it is ignoring the flags, however, setting them to obviously wrong values results in an expected error). I tried alpine (musl) and bookworm (libc) and got basically the same result as well.

Maybe I am doing something wrong, or maybe the link error here is from go and not cgo. In which case maybe go build -buildmode=pie will work, but I'm not sure how to get xcaddy to do that.

[cdaguerre]

Thanks for the tip.
Setting XCADDY_GO_BUILD_FLAGS='-buildmode=pie -ldflags="-w -s" -trimpath' does the trick.

I have no clue whether this is a workaround or an actual solution.
Do you know?

[withinboredom]

Do you know?

It's a different way of laying out the code in memory, and it should still work fine.

As a side note, I wonder if applying this might mitigate the epic crash when echoing from Fibers (see #46). It probably won't, but I never thought of using position independence to test with, especially since PIE is an x64 thing (IIRC) and we don't really see the crash on Macs (IIRC).

🤔

Please do let us know if you run into any more issues with positional independence turned on though, for now, I'm going to close this.

[cdaguerre]

thanks @withinboredom