eggos: cmd/egg: build failure when specifying build path

I tried egg build on something very simple:

(⎈ |local:default)
prologic@Jamess-iMac
Fri Aug 06 10:16:51
~/tmp/hello-eggos
 130
$ egg build .
2021/08/06 10:16:53 eggos not found in go.mod
2021/08/06 10:16:53 go get github.com/icexin/eggos
go get: added github.com/icexin/eggos v0.4.0
malformed import path "-tags": leading dash
package eggos is not in GOROOT (/usr/local/Cellar/go/1.16/libexec/src/eggos)
2021/08/06 10:18:02 exit status 1
(⎈ |local:default)
prologic@Jamess-iMac
Fri Aug 06 10:18:02
~/tmp/hello-eggos
 1
$ ls -lah
total 2.1M
drwxr-xr-x   6 prologic staff  192 Aug  6 10:18 .
drwxr-xr-x 151 prologic staff 4.8K Aug  6 10:16 ..
-rw-r--r--   1 prologic staff   80 Aug  6 10:18 go.mod
-rw-r--r--   1 prologic staff  98K Aug  6 10:18 go.sum
-rwxr-xr-x   1 prologic staff 2.0M Aug  6 10:16 hello-eggos
-rw-r--r--   1 prologic staff   73 Aug  6 10:16 main.go
(⎈ |local:default)
prologic@Jamess-iMac
Fri Aug 06 10:18:47
~/tmp/hello-eggos
 0
$ cat main.go
package main

import "fmt"

func main() {
	fmt.Println("Hello eggos!")
}
(⎈ |local:default)
prologic@Jamess-iMac
Fri Aug 06 10:18:50
~/tmp/hello-eggos
 0
$ cat go.mod
module hello-eggos

go 1.16

require github.com/icexin/eggos v0.4.0 // indirect

It might be the last 3 lines here:

malformed import path "-tags": leading dash
package eggos is not in GOROOT (/usr/local/Cellar/go/1.16/libexec/src/eggos)
2021/08/06 10:18:02 exit status 1

Bug?