Rio

Text editor & development environment

Back to the future.

A lightweight IDE in the spirit of ’90s desktop software.

adr/0007-git-by-shelling-out.mdRaw Markdown · GitHub ↗

ADR-0007: Git by shelling out to git

  • Status: Accepted
  • Date: 2026-06-24
  • Deciders: jka
  • Decision: D7

Context

Git is a first-class part of rio's workflow. The options are to link a library such as libgit2 through a compiled extension, or to run the git command and parse its machine-readable output.

Decision

rio runs git and parses its porcelain output. It has no libgit2 dependency. The git layer lives in the core (rio-core/git.tcl) on top of the headless command primitive (ADR-0015), so git works identically over a remote core.

Output formats are chosen to be unambiguous: status --porcelain=v1 -b -z (NUL-terminated, so paths with spaces or newlines are safe) and field-delimited log --pretty output. A non-zero git exit becomes a bad_request carrying git's own message; a missing git binary is an io_error.

Consequences

  • No compiled dependency, and the same behaviour wherever git is installed.
  • rio's git operations inherit git's semantics and guards, and its error messages are git's.
  • Each git feature must choose its invocation carefully. Narrow pathspecs change what git reports, as ADR-0097 and ADR-0098 found for renames and untracked folders.
  • Git's read layer started read-only; write operations were added later as separate decisions (ADR-0044, ADR-0045, ADR-0080).