Split `--snapshot installer` into `installer-exact` and `installer-updated` by jezdez · Pull Request #122 · conda/conda-self

jezdez · 2026-04-10T22:53:44Z

Summary

conda doctor base-protection --fix was stripping installer-provided packages like mamba (Miniforge) and pip from base.

The first attempt used reset(snapshot=initial-state.explicit.txt), but as @marcoesters pointed out that also downgrades any package the user updated, because diff_for_unlink_link_precs pins to the exact URLs from the snapshot.

Now we only read the names from the installer snapshot and keep those packages at whatever versions they currently are.

The old --snapshot installer is split into two:

installer-exact: exact restore, may downgrade (factory reset).
installer-updated: names from the snapshot, current versions preserved.

conda doctor base-protection --fix uses installer-updated semantics plus permanent_dependencies() (which already composes in context.plugins.self_permanent_packages from #116). Fallback on bare conda self reset is base-protection > installer-updated > current.

names_from_explicit() parses @EXPLICIT URL lines with public MatchSpec. No ProgressiveFetchExtract, no network.

initial-state.explicit.txt comes from conda/constructor#1059, shipped with Miniforge and Miniconda installers built with constructor >= 3.13.0 (Nov 2025).

Closes #121

Breaking change

--snapshot installer is gone. Safe, it was never in a release.

Also in this PR

--snapshot choices are backed by a Snapshot enum; execute dispatches via match.
PackageInfo.read_manifest classmethod replaces a module-level private helper (unrelated cleanup; happy to split out).

Test plan

unit tests for each mode, bare installer rejection, fallback ordering, and the health-check path
regression test confirms reset(uninstallable_packages=...) is strictly a keep-list (no installs), covering the rattler/libmamba coexistence case
existing tests still pass

The base-protection fix was computing the keep-list from permanent_dependencies(), which only includes conda, plugins, and their deps. This caused installer-provided packages like mamba (in Miniforge) to be removed during the reset step. Now the fix checks for the installer snapshot (initial-state.explicit.txt) and uses it for the reset, preserving whatever the installer shipped. Falls back to permanent_dependencies() when no snapshot exists. Closes #121

…aller-packages

Addresses Marco's review: resetting base with the installer snapshot via diff_for_unlink_link_precs would downgrade packages the user has updated (e.g. mamba in Miniforge). Splits the ambiguous `installer` choice into two explicit options: - `installer-exact`: restores the exact installer state (may downgrade). - `installer-updates`: keeps the installer-shipped package names at their currently installed versions (no downgrade). `conda doctor base-protection --fix` now uses the names-only strategy so it no longer downgrades installer-provided packages. Auto-fallback order becomes base-protection > installer-updates > current. Adds `names_from_explicit()` that parses a CEP-23 @explicit file without fetching, using only public conda APIs (MatchSpec + EXPLICIT_MARKER).

…staller-exact

…aller-packages # Conflicts: # tests/test_cli_reset.py

Per review: reserve assert for tests. The invariant "snapshot_choice is set => reset_file is set" is established earlier, so we reorder the dispatch to lead with the installer-updated branch whose condition (`reset_file is not None`) doubles as the type narrowing mypy needs, and fall through to the other branches otherwise.

Replace the string-literal choices and TypedDict/dict dispatch table in `conda self reset` with an `enum.Enum` that owns each snapshot's display name and on-disk file path. The `execute` function now dispatches via a `match` statement, which makes the exhaustiveness explicit and lets mypy narrow `reset_file` without an assert. Also rename `_FALLBACK_ORDER` to `FALLBACK_ORDER` (it's referenced by tests, so the leading underscore was misleading) and expand the test suite to cover: - `--snapshot current` dispatch - `installer-exact` with a missing snapshot file raises FileNotFoundError - invalid `--snapshot` values are rejected - `--help` lists all four snapshot modes - `Snapshot.display_name` and `Snapshot.file_path` unit tests - regression: `reset(uninstallable_packages=...)` never installs (keep-list semantics, covering the conda-libmamba-solver / conda-rattler-solver coexistence case)

Promote `_file_paths_from_extracted_package` from a module-level private helper to `PackageInfo.read_manifest`, a public classmethod. The helper is only used by `PackageInfo.from_record`, so scoping it to the class and giving it an intent-focused name (it reads the on-disk file manifest, falling back from info/paths.json to info/files) removes an unnecessary module-level private symbol. Also switch embedded path literals like `pkg_path / "info/paths.json"` to the idiomatic chained form `pkg_path / "info" / "paths.json"`.

jezdez · 2026-04-22T07:45:28Z

@marcoesters — two updates on this PR:

f426ffe refactors --snapshot away from string literals and the TypedDict dispatch table into an enum.Enum whose members own their display name and conda-meta/*.txt file path. execute now dispatches via a match statement, which narrows reset_file without the assert you flagged. On your solver-coexistence concern: tests expanded from 12 to 29, including a parameterized regression test that stubs PrefixSetup and confirms reset(uninstallable_packages=...) only ever unlinks (keep-list semantics) — so the conda-libmamba-solver / conda-rattler-solver case you described cannot lead to both being installed after a reset.
e8a4f2f is unrelated cleanup I folded in: promotes a module-level helper to PackageInfo.read_manifest (public classmethod) and normalizes some pathlib joins. Happy to split it into a separate PR if you'd rather keep this one focused.

jezdez · 2026-04-22T07:47:29Z

Jesus, Opus 4.7 is NOT good at keeping it straight, those comments are weird!

- reset, quickstart: now show `installer-provided (with updates)` snapshot message - base-protection: uses the new installer-updated strategy in the fix step; tighten comment to drop "to essentials" (installer-provided packages are preserved) - remove: add a `--force --dry-run` follow-up to showcase the override, and reword the comment since permanent packages are now protected rather than unremovable

The WHAT_TO_EXPECT preamble on `conda self reset` claimed the command would reset base to only conda, its plugins, and their dependencies -- but since the installer-updated snapshot became the default (#122), the reset also preserves installer-provided packages. The demos surfaced the contradiction between this preamble and the trailing "installer-provided (with updates) snapshot" success line. - Split WHAT_TO_EXPECT into snapshot/essentials variants and print the right one after snapshot resolution - Update the matching prose in docs/features.md and docs/quickstart.md - Reword the reset/quickstart tape comments to "installer-provided snapshot" - Re-record reset, quickstart, and base-protection demos

jezdez added 4 commits April 11, 2026 00:53

Clean up test file: top-level imports, remove section comments

5e45275

Use pytest.mark.parametrize to consolidate test cases

9850598

Fix pre-commit: ruff format and mypy type annotations

8afb71e

jezdez mentioned this pull request Apr 13, 2026

Overhaul documentation with Diataxis structure and VHS demos #120

Merged

6 tasks

jezdez requested a review from marcoesters April 13, 2026 12:44

Merge branch 'main' into fix-121-preserve-installer-packages

88dfa25

soapy1 mentioned this pull request Apr 13, 2026

Add configurable permanent packages setting #116

Merged

4 tasks

jezdez requested a review from soapy1 April 14, 2026 10:04

marcoesters reviewed Apr 14, 2026

View reviewed changes

Comment thread conda_self/health_checks/base_protection.py

jezdez added 2 commits April 20, 2026 16:47

Merge remote-tracking branch 'origin/main' into fix-121-preserve-inst…

842a8db

…aller-packages

jezdez changed the title ~~Use installer snapshot for base-protection reset~~ Split --snapshot installer into installer-exact and installer-updates Apr 20, 2026

jezdez requested a review from marcoesters April 20, 2026 15:09

jezdez added 2 commits April 20, 2026 17:12

Fix pre-commit: ruff format and mypy type narrowing

395087d

Rename installer-updates to installer-updated for parallelism with in…

c7ba579

…staller-exact

jezdez changed the title ~~Split --snapshot installer into installer-exact and installer-updates~~ Split --snapshot installer into installer-exact and installer-updated Apr 20, 2026

Merge remote-tracking branch 'origin/main' into fix-121-preserve-inst…

1fe6232

…aller-packages # Conflicts: # tests/test_cli_reset.py

marcoesters reviewed Apr 21, 2026

View reviewed changes

Comment thread conda_self/cli/main_reset.py Outdated

Comment thread conda_self/cli/main_reset.py Outdated

jezdez added 3 commits April 22, 2026 08:36

jezdez requested a review from marcoesters April 22, 2026 07:57

Fix pre-commit: ruff format and TC003

77085d4

marcoesters approved these changes Apr 22, 2026

View reviewed changes

jezdez merged commit ca7d3ff into main Apr 22, 2026
23 checks passed

jezdez deleted the fix-121-preserve-installer-packages branch April 22, 2026 15:48

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Split `--snapshot installer` into `installer-exact` and `installer-updated`#122

Split `--snapshot installer` into `installer-exact` and `installer-updated`#122
jezdez merged 14 commits into
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fix-121-preserve-installer-packages

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Summary

Breaking change

Also in this PR

Test plan

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