I am dropping support for versions of Mercurial older than 2.1.1 (released in May, 2012). This is the first version that: (a) has phases and (b) does not exit 1 when hg pull succeeds but fetches no changes.

After changes connected to T13546, the git workflow now looks like this:

After near-future changes connected to T13546 this is ripe for implementation, but I don't think it has come up again in ~6 years so I'm not sure it's actually worth improving. arc has also warned about abandoned revisions for a long time, which may have mooted this. My expectation is that the modern behavior is clear and the remedy is simple (arc land --revision 123) but I'm open to reconsidering this once the changes connected to T13546 have stabilized, if it's still an issue then.

After near-future changes connected to T13546, arc.land.onto (previously arc.land.onto.default) has higher priority than upstream branches.

Changes connected to T13546 address this, see T13547 for a preview of new behavior.

See PHI1013, which would like a way to specify that the branch you want to merge into might be different from the name of the branch you want to push into the remote.

I think the general shape of this is:

arc diff has a lot of code to deal with handling untracked or uncommitted changes in the working copy. The major motivations for arc caring about this are:

I'm not sure --use-commit-message has any real use cases.

Piledriver would also benefit from having some functional equivalent of destroying an Almanac resource. This can be implemented as a piledriver.destroyed property, but a formal disabled state would be cleaner. PHI1331 is vaguely related.

• When Piledriver destroys a resource pile, it's helpful if it can read the entire authoritative state from sources by using only a pile ID.
  • EC2 can do this with "DescribeTags".
  • Almanac currently can not. Almanac types should support searching by property value.
    • This could be directly on almanac.*.search.
    • Or this could be generic, via T12799.

Problem 2: Arcanist does not check that messages emitted by linters have a valid line number.

Problem 3: The cpplint unit tests fail, and the failure appears to be pre-existing and significant.

• Problem 4: If a file ends in non-newline whitespace, the text linter may raise a message which removes that line. The renderer then tries to highlight part of it, which fatals.

Here's a simplified reproduction case for "Problem 1":

• Problem 1: cpplint may raise messages at line 0, but arcanist can not render these messages after the severity of runtime-level errors was increased in D21044.

Effectively mooted by T13542.

I've written some Terraform-class tooling which can likely automate all the actual hardware allocations. This needs some more work, but I believe the tricky stuff (mostly: representing resources and allowing templating to reference resources which haven't been built yet) is at least working.

Subnet/NAT issues in T12816.

Continued in T13542.

The major offender here (services per instance) was fixed by updating caching, and I destroyed all the old services. This is perhaps spiritually continued in T13542.

Continued in T13542.

Continued in T13542. I wrote a Terraform/CloudFormation-style service in PHP over the last couple of days.

Continued in T13542.

Committer identities ... they're currently stored in a JSON blob so there's no efficient way to query them.

Is there a way to find which object(s) an (unmapped) identity was discovered on?

• In previews, suggestions aren't highlighted properly (likely just missing CSS).