Make olm optional

[rumpelsepp]

Since the olm stuff depends on C libraries, it would be nice if the c dep could be disabled with build tags.

[tulir]

It already is optional: the crypto module isn't imported from any other module

[rumpelsepp]

Hmm, when I go get -u my project it complains:

$ go get -u ...
go: downloading maunium.net/go/mautrix v0.7.1-0.20200806170505-920619205aa2
# maunium.net/go/mautrix/crypto/olm
../../../go/pkg/mod/maunium.net/go/mautrix@v0.7.1-0.20200806170505-920619205aa2/crypto/olm/account.go:4:11: fatal error: olm/olm.h: No such file or directory
    4 | // #include <olm/olm.h>
      |           ^~~~~~~~~~~
compilation terminated

Any ideas? The code currently only does a login to a matrix server.

[tulir]

You probably shouldn't ... there. Just go build or go install should work

[rumpelsepp]

Probably. That's how I update the go dependencies along my projects. But it seems to work a bit too recursively…