Question

Git has the cat-file command to inspect internal files, e.g. git cat-file blob 557db03 will show the contents of the object whose hash starts with 557db03.

Are there similar tools for mercurial that allow me to look at all the different data files that merfcurial uses internally?

Answer 1

Try hg --debug help and you can see the list of all the debug commands:

 debugancestor:
      find the ancestor revision of two revisions in a given index
 debugbuilddag:
      builds a repo with a given DAG from scratch in the current empty repo
 debugbundle:
      lists the contents of a bundle
 debugcheckstate:
      validate the correctness of the current dirstate
 debugcommands:
      list all available commands and options
 debugcomplete:
      returns the completion list associated with the given command
 debugdag:
      format the changelog or an index DAG as a concise textual description
 debugdata:
      dump the contents of a data file revision
 debugdate:
      parse and display a date
 debugdiscovery:
      runs the changeset discovery protocol in isolation
 debugfileset:
      parse and apply a fileset specification
 debugfsinfo:
      show information detected about current filesystem
 debuggetbundle:
      retrieves a bundle from a repo
 debugignore:
      display the combined ignore pattern
 debugindex:
      dump the contents of an index file
 debugindexdot:
      dump an index DAG as a graphviz dot file
 debuginstall:
      test Mercurial installation
 debugknown:
      test whether node ids are known to a repo
 debugpushkey:
      access the pushkey key/value protocol
 debugrebuildstate:
      rebuild the dirstate as it would look like for the given revision
 debugrename:
      dump rename information
 debugrevlog:
      show data and statistics about a revlog
 debugrevspec:
      parse and apply a revision specification
 debugsetparents:
      manually set the parents of the current working directory
 debugstate:
      show the contents of the current dirstate
 debugsub:
      (no help text available)
 debugwalk:
      show how files match on given patterns
 debugwireargs:
      (no help text available)

There are a lot of them, and they pretty much expose everything.