First time deploy plugin and failed.Need help

This is my first time deploy my plugin,it is here https://github.com/zhshch2002/caddy-webp

It can convert JPG/PNGs to webp format.

when I deploy it on dashboard

plugin deploy failed
go build github.com/zhshch2002/caddy-webp@v0.0.1: build failed: GOOS=darwin GOARCH=amd64 GOARM=: exit status 2

2020/03/23 03:50:25 exec [/tmp/buildenv_03-23-0350.045656790/main] /usr/local/bin/go mod init tmp/caddy/main
go: creating new go.mod: module tmp/caddy/main
2020/03/23 03:50:26 exec [/tmp/buildenv_03-23-0350.045656790/main] /usr/local/bin/go mod edit -replace github.com/mholt/caddy=github.com/caddyserver/caddy@latest
2020/03/23 03:50:26 exec [/tmp/buildenv_03-23-0350.045656790/main] /usr/local/bin/go get -d -x github.com/zhshch2002/caddy-webp@v0.0.1
# get https://proxy.golang.org/github.com/caddyserver/caddy/@v/list
# get https://proxy.golang.org/github.com/caddyserver/caddy/@v/list: 200 OK (0.255s)
go: finding github.com v0.0.1
# get https://proxy.golang.org/github.com/@v/v0.0.1.info
go: finding github.com/zhshch2002 v0.0.1
# get https://proxy.golang.org/github.com/zhshch2002/@v/v0.0.1.info
# get https://proxy.golang.org/github.com/@v/v0.0.1.info: 410 Gone (0.022s)
# get https://proxy.golang.org/github.com/zhshch2002/@v/v0.0.1.info: 410 Gone (0.131s)
2020/03/23 03:50:26 exec [/tmp/buildenv_03-23-0350.045656790/main] /usr/local/bin/go get -d -x github.com/caddyserver/caddy@v1.0.4
# get https://proxy.golang.org/github.com/caddyserver/caddy/@v/list
# get https://proxy.golang.org/github.com/caddyserver/caddy/@v/list: 200 OK (0.082s)
# get https://proxy.golang.org/github.com/zhshch2002/caddy-webp/@v/list
# get https://proxy.golang.org/github.com/zhshch2002/caddy-webp/@v/list: 200 OK (0.132s)
2020/03/23 03:50:27 exec [/tmp/buildenv_03-23-0350.045656790/main] /usr/local/bin/go mod vendor
2020/03/23 03:50:27 exec [/tmp/buildenv_03-23-0350.045656790/main] /bin/bash /tmp/buildenv_03-23-0350.045656790/main/rewrite.bash
2020/03/23 03:50:30 exec [/tmp/buildenv_03-23-0350.045656790/main] /usr/local/bin/go mod edit -dropreplace github.com/mholt/caddy
2020/03/23 03:50:30 exec [/tmp/buildenv_03-23-0350.045656790/main] /usr/local/bin/go mod edit -droprequire github.com/mholt/caddy
2020/03/23 03:50:31 exec [/] /usr/bin/git clone https://github.com/zhshch2002/caddy-webp.git /tmp/buildenv_03-23-0350.045656790/repo
Cloning into '/tmp/buildenv_03-23-0350.045656790/repo'...
2020/03/23 03:50:31 exec [/tmp/buildenv_03-23-0350.045656790/repo] /usr/bin/git checkout v0.0.1
Note: checking out 'v0.0.1'.

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by performing another checkout.

If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -b with the checkout command again. Example:

  git checkout -b <new-branch-name>

HEAD is now at e1eaa96 init
2020/03/23 03:50:31 exec [/tmp/buildenv_03-23-0350.045656790/repo] /usr/local/bin/go vet github.com/zhshch2002/caddy-webp/...
2020/03/23 03:51:19 exec [/tmp/buildenv_03-23-0350.045656790/repo] /usr/local/bin/go test -race github.com/zhshch2002/caddy-webp/...
?   	github.com/zhshch2002/caddy-webp	[no test files]
2020/03/23 03:52:10 GOOS=darwin GOARCH=amd64 GOARM= go build
2020/03/23 03:52:10 exec [/tmp/buildenv_03-23-0350.045656790/main] /usr/local/bin/go build -mod=vendor -p 4 -o /tmp/buildenv_03-23-0350.045656790/builds/caddy_build_check
# github.com/chai2010/webp
vendor/github.com/chai2010/webp/webp.go:17:9: undefined: webpGetInfo
vendor/github.com/chai2010/webp/webp.go:21:20: undefined: webpDecodeGray
vendor/github.com/chai2010/webp/webp.go:34:20: undefined: webpDecodeRGB
vendor/github.com/chai2010/webp/webp.go:47:20: undefined: webpDecodeRGBA
vendor/github.com/chai2010/webp/webp.go:63:14: undefined: webpDecodeGrayToSize
vendor/github.com/chai2010/webp/webp.go:77:14: undefined: webpDecodeRGBToSize
vendor/github.com/chai2010/webp/webp.go:91:14: undefined: webpDecodeRGBAToSize
vendor/github.com/chai2010/webp/webp.go:104:7: undefined: toGrayImage
vendor/github.com/chai2010/webp/webp.go:105:14: undefined: webpEncodeGray
vendor/github.com/chai2010/webp/webp.go:114:14: undefined: webpEncodeRGB
vendor/github.com/chai2010/webp/webp.go:114:14: too many errors


sense sth related to github.com/chai2010/webp/
is there sth wrong with cgo?