snapcraft 2.43 snap can't access to HTTPS APT sources

[林博仁(Buo-ren Lin)]

Found a bunch of the following error:

```
Failed to update the package cache: Some files could not be downloaded:

E:The method driver /snap/snapcraft/1803/usr/lib/apt/methods/https could not be found.
W:Is the package apt-transport-https installed?
```

[Olivier Tilloy (osomon)]

The same error has been reported to me by someone else who uses custom repositories on their build machine.

I cannot get my hands on a 2.42 snapcraft snap to check whether it contained the https method and it was removed in 2.43.

[Sergio Schvezov (sergiusens)]

https is indeed missing.
Fix comming.

[Sergio Schvezov (sergiusens)]

https://github.com/snapcore/snapcraft/pull/2244

[Sergio Schvezov (sergiusens)]

I suspect projects encountering this issue are not using a clean environment or adding remote sources (as in not part of Ubuntu) to the environment where things are building, is this a correct assessment?

[Olivier Tilloy (osomon)]

I think so, although I haven't observed the issue firsthand.

[林博仁(Buo-ren Lin) (brlin)]

@sergiusens

> is this a correct assessment?

Yes, as `snapcraft` happily runs on these environments I happened to make it run on my working system for smaller sized snaps like Snapcraft Template Plus and Tidy. This bug doesn't occur in other snaps I choose to run in LXD/Docker.

[林博仁(Buo-ren Lin) (brlin)]

An example APT source that can trigger this issue is the Git Large File System's official repo, but any HTTPS APT source should do.

[Sergio Schvezov (sergiusens)]

Thanks buo-ren-lin, I do have a fix and know how to trigger the regression, I am just looking for a very stable repo to use in a test to not re-introduce this regression. I would like to avoid create a fake https server for this as that would involved cert management among others.