`//go:embed <path to file in parent directory>` doesn't work

[gucio321]

What version of Go are you using (go version)?

go version go1.16.4 linux/amd64

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

go env Output

GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/user/.cache/go-build"
GOENV="/home/user/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/user/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/user/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="go1.16.4"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/dev/null"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build3225948580=/tmp/go-build -gno-record-gcc-switches"

What did you do?

There is a following package:

• main.go
• README.md
• assets:
  • assets.go

assets.go contains package assets loaded with //go:embed directive.
I'd like to add README.md file to assets.go, but //go:embed ../README.md doesn't work

What did you expect to see?

the program should compile and work fine.

What did you see instead?

assets/assets.go:59:12: pattern ../README.md: invalid pattern syntax

[seankhliao]

This is intentional and documnted

Patterns may not contain ‘.’ or ‘..’ or empty path elements, nor may they begin or end with a slash.

[gucio321]

@seankhliao is it possible to make it a feature request?

[seankhliao]

It still can't cross module boundaries, and if it's in the same module you can just put the embed directive in a go file in the parent directory

[gucio321]

yah, this solution is possible, but it would be a bit crazy.
I'd need to add go:embed directive in main.go and pass on embeded variable to my app? it doesn't seem right.

[gucio321]

@seankhliao maybe go:embed in module area could be allowed?

[seankhliao]

This was an explicit design decision:

Because embed.Files implements fs.FS, it cannot provide access to files with names beginning with .., so files in parent directories are also disallowed entirely, even when the parent directory named by .. does happen to be in the same module.

ref: https://go.googlesource.com/proposal/+/master/design/draft-embed.md

[lonnyzhang423]

It still can't cross module boundaries, and if it's in the same module you can just put the embed directive in a go file in the parent directory

@gucio321 There is no need to put embed files into child directories, * can be used to match everything int the current directory.

I found this in embed draft.
https://go.googlesource.com/proposal/+/master/design/draft-embed.md#go_embed-directives

[purpleidea]

There's a major bug with this:

I have the COPYING license file in my project root. But my CLI package which wants to display that text is in a subdir. And so I can't ../COPYING to embed it. I don't think you should be able to get out of the package root, but this blocks the obvious use case that we used go-bindata for :/