Just a small announcement for OPAM packagers here.
According to the new external dependencies (depexts for short) implementation in OPAM 2.0 , the
"source" depexts will not be supported anymore.
"source" depext allowed you to execute any arbitrary script as root and is usually used for installing external dependencies from source when those are not available on some or any distributions.
This is not possible anymore with OPAM 2.0. The rational is that it is too much of a security risk, the user using
opam depext has no control over what is executed and the installation process is quite arbitrary.
The last bits of
"source" depexts will be removed soon enough from the opam-repository . If you are maintaining any library that needed to use the
"source" depext in order to comply with the CI system or anything of that matter, please do not use it and add a
post-messages in case of failure telling how the users might want to install the missing dependencies in case they are not available in any or too few distributions.