mercurial (hg) equivalent of git describe --contains <commit> to find tag that has <commit> as an ancestor in its history

Question

I'm trying to use mercurial to give me the tag that contains a specific commit, just like git describe --contains, as described in documentation:

--contains

Instead of finding the tag that predates the commit, find
the tag that comes after the commit, and thus contains it.
Automatically implies --tags.

hg log -r <rev> --template '{latesttag}\n' doesn't fit the bill as it returns the most recent tag reachable from <rev>.

Has mercurial a simple way to find the tag that contains rev ?

Answer 1

Has mercurial a simple way to find the tag that contains rev?

Yes, keyword for search is "revsets"

While your (and git-doc) definition is rather dirty (which tag from a possible set), I'll show step-by-step solution for case "first tag including changeset CSID"

Testing ground

• Hg-git repo https://foss.heptapod.net/mercurial/hg-git (long history, a lot of tags)
• Latest Mercurial (THG) 6.2.1

Conditions

In order to satisfy most of the requirements of the task, for such a list of tags (part of a complete one), I decided to use a changeset between 2084 and 2089 and want to have 1.0.0b1 as result

hg-git> hg tags
tip                             2167:b963d11cc1c8
1.0.0                           2137:6f22e3887d82
1.0.0b2.post1                   2106:ff6274c7c614
1.0.0b2                         2104:d31a72cf70bd
1.0.0b1                         2089:311e9a57959e
0.10.4                          2084:bc5339fcea1e
...

our range

hg-git> hg log -r 2084:2089 -T compact
2084[0.10.4]:2082   bc5339fcea1e   2022-01-26 18:40 +0100   danchr
  NEWS: 0.10.4 release

2085   da261c503c13   2022-01-26 18:40 +0100   danchr
  Added tag 0.10.4 for changeset bc5339fcea1e

2086   ec721ee0f93b   2022-01-26 18:40 +0100   danchr
  Added signature for changeset bc5339fcea1e

2087:2083,2086   729775377f6b   2022-01-26 18:49 +0100   danchr
  merge with branch 0.10.x

2088   08347725306b   2021-12-24 13:23 +0100   danchr
  versioning: create branch 1.0.x

2089[1.0.0b1]   311e9a57959e   2021-12-24 13:21 +0100   danchr
  NEWS: 1.0b1 release

I'll use 2086 for CSID

Solution

Get all descendants of CSID

hg log -r "descendants(2086)" or it can be shorter hg log -r 2086:, but I want revsets from start (output missed due to the obviousness of the result)

Shorten the output, leaving only the tags

hg-git> hg log -r "descendants(2086) and tag()" -T compact
2089[1.0.0b1]   311e9a57959e   2021-12-24 13:21 +0100   danchr
  NEWS: 1.0b1 release

2104[1.0.0b2]   d31a72cf70bd   2022-03-10 15:58 +0100   danchr
  NEWS: 1.0b2 release

2106[1.0.0b2.post1]   ff6274c7c614   2022-03-10 16:11 +0100   danchr
  Added signature for changeset d31a72cf70bd

2137[1.0.0]   6f22e3887d82   2022-04-01 16:54 +0200   danchr
  NEWS: 1.0.0 release!

Shorten the output, leaving only the first tag

hg-git> hg log -r "first(descendants(2086) and tag())" -T compact
2089[1.0.0b1]   311e9a57959e   2021-12-24 13:21 +0100   danchr
  NEWS: 1.0b1 release

Shorten the output, leaving only needed data (changeset+tag+date f.e)

hg-git> hg log -r "first(descendants(2086) and tag())" -T "{node|short}:{tags} {date|shortdate}\n"
311e9a57959e:1.0.0b1 2021-12-24

Bonus Game

Shorten the command for easy re-use later:

revset (data of -r option) moved into [revsetalias] section (hg help revsets) of repo-hgrc or global config (hg help revsets) and one parameter cs added for using with any CSID

  [revsetalias]
  ft(cs) = first(descendants(cs) and tag())

template of output (data of -T option) moved into [templates] (hg help templating) section of...

  [templates]
  tagid = "{node|short}:{tags} {date|shortdate}\n"

and final command turns into something like

hg log -r "ft(ec721ee0f93b)" -T tagid

PS With TortoiseHG you can easy debug and visualize your revsets, using filter toolbar for defining revsets by hand and|or visual query editor for GUI