patch can conflict on not activated packages

src/cargo/core/resolver/mod.rs

@@ -811,10 +811,8 @@ impl RemainingCandidates {
  }
 }
 
-/// Attempts to find a new conflict that allows a `find_candidate` feather then the input one.
+/// Attempts to find a new conflict that allows a `find_candidate` better then the input one.
 /// It will add the new conflict to the cache if one is found.
-///
-/// Panics if the input conflict is not all active in `cx`.
 fn generalize_conflicting(
  cx: &Context,
  registry: &mut RegistryQueryer<'_>,
@@ -823,15 +821,12 @@ fn generalize_conflicting(
  dep: &Dependency,
  conflicting_activations: &ConflictMap,
 ) -> Option<ConflictMap> {
- if conflicting_activations.is_empty() {
- return None;
- }
  // We need to determine the `ContextAge` that this `conflicting_activations` will jump to, and why.
- let (backtrack_critical_age, backtrack_critical_id) = conflicting_activations
- .keys()
- .map(|&c| (cx.is_active(c).expect("not currently active!?"), c))
- .max()
-  .unwrap();
+ let (backtrack_critical_age, backtrack_critical_id) = shortcircuit_max(
+ conflicting_activations
+  .keys()
+  .map(|&c| cx.is_active(c).map(|a| (a, c))),
+ )?;
  let backtrack_critical_reason: ConflictReason =
  conflicting_activations[&backtrack_critical_id].clone();
 
@@ -923,6 +918,19 @@ fn generalize_conflicting(
  None
 }
 
+/// Returns Some of the largest item in the iterator.
+/// Returns None if any of the items are None or the iterator is empty.
+fn shortcircuit_max<I: Ord>(iter: impl Iterator<Item = Option<I>>) -> Option<I> {
+ let mut out = None;
+ for i in iter {
+ if i.is_none() {
+ return None;
+ }
+ out = std::cmp::max(out, i);
+ }
+ out
+}
+
 /// Looks through the states in `backtrack_stack` for dependencies with
 /// remaining candidates. For each one, also checks if rolling back
 /// could change the outcome of the failed resolution that caused backtracking
@@ -949,12 +957,10 @@ fn find_candidate(
  // the cause of that backtrack, so we do not update it.
  let age = if !backtracked {
  // we don't have abnormal situations. So we can ask `cx` for how far back we need to go.
- let a = cx.is_conflicting(Some(parent.package_id()), conflicting_activations);
- // If the `conflicting_activations` does not apply to `cx`, then something went very wrong
- // in building it. But we will just fall back to laboriously trying all possibilities witch
- // will give us the correct answer so only `assert` if there is a developer to debug it.
- debug_assert!(a.is_some());
- a
+ // If the `conflicting_activations` does not apply to `cx`,
+ // we will just fall back to laboriously trying all possibilities witch
+ // will give us the correct answer.
+ cx.is_conflicting(Some(parent.package_id()), conflicting_activations)
  } else {
  None
  };

tests/testsuite/patch.rs

@@ -2541,3 +2541,105 @@ foo v0.1.0 [..]
  ))
  .run();
 }
+
+// From https://github.com/rust-lang/cargo/issues/7463
+#[cargo_test]
+fn patch_eq_conflict_panic() {
+ Package::new("bar", "0.1.0").publish();
+ Package::new("bar", "0.1.1").publish();
+ let p = project()
+ .file(
+ "Cargo.toml",
+ r#"
+ [package]
+ name = "foo"
+ version = "0.1.0"
+
+ [dependencies]
+ bar = "=0.1.0"
+
+ [dev-dependencies]
+ bar = "=0.1.1"
+
+ [patch.crates-io]
+ bar = {path="bar"}
+ "#,
+ )
+ .file("src/lib.rs", "")
+ .file("bar/Cargo.toml", &basic_manifest("bar", "0.1.1"))
+ .file("bar/src/lib.rs", "")
+ .build();
+
+ p.cargo("generate-lockfile")
+ .with_status(101)
+ .with_stderr(
+ r#"[UPDATING] `dummy-registry` index
+[ERROR] failed to select a version for `bar`.
+ ... required by package `foo v0.1.0 ([..])`
+versions that meet the requirements `=0.1.1` are: 0.1.1
+
+all possible versions conflict with previously selected packages.
+
+ previously selected package `bar v0.1.0`
+ ... which satisfies dependency `bar = "=0.1.0"` of package `foo v0.1.0 ([..])`
+
+failed to select a version for `bar` which could resolve this conflict
+"#,
+ )
+ .run();
+}
+
+// From https://github.com/rust-lang/cargo/issues/11336
+#[cargo_test]
+fn mismatched_version2() {
+ Package::new("qux", "0.1.0-beta.1").publish();
+ Package::new("qux", "0.1.0-beta.2").publish();
+ Package::new("bar", "0.1.0")
+ .dep("qux", "=0.1.0-beta.1")
+ .publish();
+ let p = project()
+ .file(
+ "Cargo.toml",
+ r#"
+ [package]
+ name = "foo"
+ version = "0.1.0"
+
+ [dependencies]
+ bar = "0.1.0"
+ qux = "0.1.0-beta.2"
+
+ [patch.crates-io]
+ qux = { path = "qux" }
+ "#,
+ )
+ .file("src/lib.rs", "")
+ .file(
+ "qux/Cargo.toml",
+ r#"
+ [package]
+ name = "qux"
+ version = "0.1.0-beta.1"
+ "#,
+ )
+ .file("qux/src/lib.rs", "")
+ .build();
+
+ p.cargo("generate-lockfile")
+ .with_status(101)
+ .with_stderr(
+ r#"[UPDATING] `dummy-registry` index
+[ERROR] failed to select a version for `qux`.
+ ... required by package `bar v0.1.0`
+ ... which satisfies dependency `bar = "^0.1.0"` of package `foo v0.1.0 ([..])`
+versions that meet the requirements `=0.1.0-beta.1` are: 0.1.0-beta.1
+
+all possible versions conflict with previously selected packages.
+
+ previously selected package `qux v0.1.0-beta.2`
+ ... which satisfies dependency `qux = "^0.1.0-beta.2"` of package `foo v0.1.0 ([..])`
+
+failed to select a version for `qux` which could resolve this conflict"#,
+ )
+ .run();
+}