XCADDY_GO_BUILD_FLAGS is not behaving well with windows builds

[YoungMind1]

This command works: XCADDY_GO_BUILD_FLAGS="-ldflags '-w -s -extldflags=-static'" xcaddy build
But this is not working: GOOS='windows' GOARCH='amd64' XCADDY_GO_BUILD_FLAGS="-ldflags '-w -s'" xcaddy build

second command's output:

2025/01/09 13:31:01 [INFO] absolute output file path: /tmp/tmp.FgBTzEnSTP/caddy.exe
2025/01/09 13:31:01 [INFO] Temporary folder: /tmp/buildenv_2025-01-09-1331.2596660125
2025/01/09 13:31:01 [INFO] Writing main module: /tmp/buildenv_2025-01-09-1331.2596660125/main.go
package main

import (
	caddycmd "github.com/caddyserver/caddy/v2/cmd"

	// plug in Caddy modules here
	_ "github.com/caddyserver/caddy/v2/modules/standard"
)

func main() {
	caddycmd.Main()
}
2025/01/09 13:31:01 [INFO] Initializing Go module
2025/01/09 13:31:01 [INFO] exec (timeout=0s): /usr/bin/go mod init caddy 
go: creating new go.mod: module caddy
go: to add module requirements and sums:
	go mod tidy
2025/01/09 13:31:01 [INFO] Pinning versions
2025/01/09 13:31:01 [INFO] exec (timeout=0s): /usr/bin/go get -v -ldflags -w -s -extldflags=-static github.com/caddyserver/caddy/v2 
go: github.com/caddyserver/caddy/[email protected] requires go >= 1.22.3; switching to go1.22.10
go: accepting indirect upgrade from [email protected] to 1.22.3
go: upgraded go 1.22.2 => 1.22.3
go: added toolchain go1.22.10
go: added github.com/beorn7/perks v1.0.1
go: added github.com/caddyserver/caddy/v2 v2.9.1
go: added github.com/caddyserver/certmagic v0.21.6
go: added github.com/caddyserver/zerossl v0.1.3
go: added github.com/cespare/xxhash/v2 v2.3.0
go: added github.com/francoispqt/gojay v1.2.13
go: added github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572
go: added github.com/google/pprof v0.0.0-20231212022811-ec68065c825e
go: added github.com/google/uuid v1.6.0
go: added github.com/klauspost/cpuid/v2 v2.2.9
go: added github.com/libdns/libdns v0.2.2
go: added github.com/mholt/acmez/v3 v3.0.0
go: added github.com/miekg/dns v1.1.62
go: added github.com/onsi/ginkgo/v2 v2.13.2
go: added github.com/prometheus/client_golang v1.19.1
go: added github.com/prometheus/client_model v0.5.0
go: added github.com/prometheus/common v0.48.0
go: added github.com/prometheus/procfs v0.12.0
go: added github.com/quic-go/qpack v0.5.1
go: added github.com/quic-go/quic-go v0.48.2
go: added github.com/zeebo/blake3 v0.2.4
go: added go.uber.org/mock v0.4.0
go: added go.uber.org/multierr v1.11.0
go: added go.uber.org/zap v1.27.0
go: added go.uber.org/zap/exp v0.3.0
go: added golang.org/x/crypto v0.31.0
go: added golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842
go: added golang.org/x/mod v0.18.0
go: added golang.org/x/net v0.33.0
go: added golang.org/x/sync v0.10.0
go: added golang.org/x/sys v0.28.0
go: added golang.org/x/term v0.27.0
go: added golang.org/x/text v0.21.0
go: added golang.org/x/time v0.7.0
go: added golang.org/x/tools v0.22.0
go: added google.golang.org/protobuf v1.35.1
2025/01/09 13:31:03 [INFO] exec (timeout=0s): /usr/bin/go get -v -ldflags -w -s -extldflags=-static  
2025/01/09 13:31:06 [INFO] Build environment ready
2025/01/09 13:31:06 [INFO] exec (timeout=0s): /usr/bin/go list -m github.com/caddyserver/caddy/v2 -ldflags -w -s -extldflags=-static 
go: module -ldflags: not a known dependency
go: module -w -s -extldflags=-static: not a known dependency
2025/01/09 13:31:06 [INFO] Cleaning up temporary folder: /tmp/buildenv_2025-01-09-1331.2596660125
2025/01/09 13:31:06 [FATAL] exit status 1

[mohammed90]

What do you mean "not working"? What happens? What's printed?

[YoungMind1]

@mohammed90 Oh, I totally forgot to add context :). description is updated.

[mohammed90]

Found it. It's because the flags are appended to the end as argument instead of right after the sub-command of go, so the go command assumes it's a Go module in that position. The relevant code paths are here, if anyone wants to beat us to the fix:

xcaddy/builder.go

Lines 98 to 100 in eb894be

	if b.OS == "windows" {
	// get version string, we need to parse the output to get the exact version instead tag, branch or commit
	cmd := buildEnv.newGoBuildCommand(ctx, "list", "-m", buildEnv.caddyModulePath)

xcaddy/environment.go

Lines 249 to 252 in eb894be

	func (env environment) newGoBuildCommand(ctx context.Context, args ...string) *exec.Cmd {
	cmd := env.newCommand(ctx, utils.GetGo(), args...)
	return parseAndAppendFlags(cmd, env.buildFlags)
	}