Wallet Extension does not work when built

[jamescarlyle]

Steps to reproduce, following instructions at https://github.com/obscuronet/go-obscuro/tree/main/tools/walletextension:

jwgcarlyle@penguin:~/github.com/obscuronet/go-obscuro/tools/walletextension$ env GOOS=linux GOARCH=amd64 go build -o ../bin/wallet_extension_linux_amd64 .
jwgcarlyle@penguin:~/github.com/obscuronet/go-obscuro/tools/walletextension$ chmod +777 ../bin/wallet_extension_linux_amd64 
jwgcarlyle@penguin:~/github.com/obscuronet/go-obscuro/tools/walletextension$ ../bin/wallet_extension_linux_amd64 
../bin/wallet_extension_linux_amd64: line 1: syntax error near unexpected token `newline'
../bin/wallet_extension_linux_amd64: line 1: `!<arch>'

[jamescarlyle]

I'm building with go version go1.17.3 linux/amd64
in a debian environment on a chromebook, but don't think that should make a difference