Error building Mailsync


I’m trying to build mailsync using the latest code from the master branch, commit e079b209eb5e23195df59a12ffbac9503320029a

After building SSL it seems to fail at this step, with no clear error indicating what went wrong

Building and installing curl-7.70.0...
Reading package lists... Done
E: You must put some 'source' URIs in your sources.list

Has anyone been able to build the latest from master? Or which branch or commit would be a working one?

Also, is there a build guide somewhere? I could not find one so i’m not sure if i may be missing dev tools or other dependencies that could cause this problem