CheckForUpdates fails

[laurentbartholdi]

Due to a change on the gap website, that gap-system.org does not accept anymore http requests, the command "CheckForUpdates" does not work anymore.

In fact, it would also be nice to implement an https client, since http seems to be less and less used.

[ChrisJefferson]

While we should look for this, unfortunately https is a massive undertaking compared to http (it's easy to write a http client, and basically impossible to write a https client). We will have to pull in an external https library (I have no idea how hard that would be..)

[ChrisJefferson]

This should work again now. However, long term we need a new plan, as it won't work forever.

[ChrisJefferson]

I should say, this is because we re-enable http access to gap-system, but I'm told we can only have it for a year or so, then it needs turning off.

[olexandr-konovalov]

The switch to https also has an impact on UnitLib (gap-packages/unitlib#3). It may also eventually have some impact on AtlasRep, which now uses IO or wget to retrieve remote data.

[markuspf]

I recommend using https://github.com/gap-packages/curlInterface

[fingolfin]

It might be best to remove CheckForUpdates, or at least make it print a big fat deprecation message. And perhaps add a similar command to @mtorpey's https://github.com/gap-packages/PackageManager

[mtorpey]

I've added an issue to PackageManager: gap-packages/PackageManager#33

[fingolfin]

the issue @mtorpey mentioned was resolved in the meantime, nice. But it asked for something slightly different. I've now also submitted this issue: gap-packages/PackageManager#46