2025-07-30 Conda Community Meeting

Zoom link · What time is the meeting in my time zone

Various parts of the conda community gather on a regular basis. This meeting brings together all of these sub-communities for a community wide call.

Attendees

Name	Initials	Affiliation	GH Username
Cheng H. Lee	CHL	Anaconda/cf	chenghlee
Ryan Keith	RSK	Anaconda	ryanskeith
John Kirkham	JK	NVIDIA/cf	jakirkham
Marco Esters	ME	Anaconda	marcoesters
Katherine Kinnaman	KK	Anaconda	kathatherine
Jaime Rodríguez-Guerra	JRG	Quansight/cf	jaimergp
Jannis Leidel	JL	Anaconda/cf	jezdez

9 people in total

Introductions

• Marco: Everything-installers at Anaconda
• Ryan: SWE at Anaconda, now part of the conda open-source team
• Katherine: Documentation efforts at Anaconda
• Maureen: Technical Writer at Anaconda

Announcements

• None

New Agenda Items

• WV: Demo: Conditional and Optional Dependencies in rattler-build
  • Conditional requirements merged support in resolvo (lowest-level part of the stack)
  • Optional dependencies (extras) are expressed as conditions
  • Condition expressions resolve match-specs, support logical operators like and/or; precedence with parentheses. Examples: bzip2 *; if rattler-build >=0.44.
  • Opt. deps. taken from PyPI world (extras)
  • extras encoded as package[extras=[group-name, group-name-2]]
  • CEP at https://github.com/conda/ceps/pull/111 (flags not yet implemented)
  • JRG: Can a group depend on another group in the same package?
    • WV: Yes, via package-name [extras=[other-group]]. No extra syntax needed.
  • RK: What gets generated? Another set of packages?
    • WV: No, a new metadata standard is necessary (see CEP); e.g. extra_depends: {}.
  • RK: Do extras act as run_constrained? What happens if someone adds a package that would be constrained by an extra?
    • WV: No, only considered if they are explicitly requested. But maybe there's a good use case for that.
  • JK: What can be compared in the conditions?
    • WV: The full matchspec syntax is supported, included virtual packages. ${{Jinja}} is also supported.
  • JK: How does this affect repodata patching? JLAP, sharding?
    • WV: Should not affect patching. Extras and flags should be patchable too. JLAP and sharding shouldn't be affected; same technical approach. These three features are part of the same repodata bump (v2), that's why they are part of the same CEP.
  • JL: if in the expression? Looks a bit redundant. Same discussion in PEP 508, ended up being dropped due to user confusion feedback.
    • JRG: Agree that if looks confusing, especially if mixed with the recipe.yaml {if: ..., then: ..., else:...} and ${{ value if expr else value }} syntaxes that already exist.
  • JL: Advocates for separate CEPs for each feature. Even if they will all share the same repodata bump.
    • WV: Fair enough about splitting.