Two spellings of one version constraint are one source (#647 E4.2 follow-up)

[Sunrisepeak]

Self-review of #650, before 2026.9.16.1 is released, found that the gate #647 E4.2 added refuses a manifest the previous release builds. The release dispatch was cancelled for this; 2026.9.16.1 ships from this branch instead.

The reading

[dependencies]
fmtlib.fmt = ">=11.0.0"
[feature-deps.extra]
fmtlib.fmt = { version = ">= 11.0.0", reexport = true }

engine	result
2026.9.15.2 (released)	builds, no error and no warning
2026.9.16.1 (f4529b2a)	error: ... restates the dependency 'fmtlib.fmt' with version = ">= 11.0.0", while the declaration in effect on this row names version = ">=11.0.0".

One space turns a build that worked yesterday into a refusal.

The change

A [feature-deps] restatement must name its dependency's source, and one naming another source is refused rather than silently dropped. The comparison was made on the bytes. A path was normalised first, so a path dependency was already judged on what it means; a version constraint was not. The judgement is now made on what the declarations mean -- the constraint is compared with its whitespace removed -- while the message still shows each declaration as it was written, so a genuine disagreement reads as the manifest spells it.

The same review asked why the first custom-index sync does not go through decide_for_miss/apply. It should not: that pair's debounce and one-sync-per-process guard are about the index that resolves a dependency, while this sync creates a local copy of a different set of repositories that nothing else will create, so taking the guard would let an earlier refresh of the builtin index suppress a clone the build cannot proceed without. Only the opt-outs are shared. The comment now states which half is taken and why the other is not.

Verification

• e2e 711 gains a leg: a restatement differing only in whitespace is not refused, and one naming >=9.9.8 against >=9.9.9 still is. On f4529b2a the first half fails with the refusal quoted above.
• Unit tests: 121 passed, 0 failed.
• e2e 187, 710, 711, 712, 713, 714 pass locally.