Allow unpublishable crates to be packaged

src/cargo/ops/cargo_package.rs

@@ -249,7 +249,9 @@ pub fn package(ws: &Workspace<'_>, opts: &PackageOpts<'_>) -> CargoResult<Vec<Fi
         } else {
             let tarball = create_package(ws, &pkg, ar_files, local_reg.as_ref())?;
             if let Some(local_reg) = local_reg.as_mut() {
-                local_reg.add_package(ws, &pkg, &tarball)?;
+                if pkg.publish() != &Some(Vec::new()) {
+                    local_reg.add_package(ws, &pkg, &tarball)?;
+                }
             }
             outputs.push((pkg, opts, tarball));
         }
@@ -290,7 +292,10 @@ fn get_registry(
     if let RegistryOrIndex::Registry(reg_name) = reg {
         for pkg in pkgs {
             if let Some(allowed) = pkg.publish().as_ref() {
-                if !allowed.iter().any(|a| a == &reg_name) {
+                // If allowed is empty (i.e. package.publish is false), we let it slide.
+                // This allows packaging unpublishable packages (although packaging might
+                // fail later if the unpublishable package is a dependency of something else).
+                if !allowed.is_empty() && !allowed.iter().any(|a| a == &reg_name) {
                     bail!(
                         "`{}` cannot be packaged.\n\
                          The registry `{}` is not listed in the `package.publish` value in Cargo.toml.",

src/cargo/ops/registry/mod.rs

@@ -325,9 +325,19 @@ pub(crate) struct RegistrySourceIds {
 
 /// If this set of packages has an unambiguous publish registry, find it.
 pub(crate) fn infer_registry(pkgs: &[&Package]) -> CargoResult<Option<RegistryOrIndex>> {
-    if pkgs[1..].iter().all(|p| p.publish() == pkgs[0].publish()) {
-        // If all packages have the same publish settings, we take that as the default.
-        match pkgs[0].publish().as_deref() {
+    // Ignore "publish = false" packages while inferring the registry.
+    let publishable_pkgs: Vec<_> = pkgs
+        .iter()
+        .filter(|p| p.publish() != &Some(Vec::new()))
+        .collect();
+
+    let Some((first, rest)) = publishable_pkgs.split_first() else {
+        return Ok(None);
+    };
+
+    // If all packages have the same publish settings, we take that as the default.
+    if rest.iter().all(|p| p.publish() == first.publish()) {
+        match publishable_pkgs[0].publish().as_deref() {
             Some([unique_pkg_reg]) => {
                 Ok(Some(RegistryOrIndex::Registry(unique_pkg_reg.to_owned())))
             }
@@ -346,7 +356,7 @@ pub(crate) fn infer_registry(pkgs: &[&Package]) -> CargoResult<Option<RegistryOr
             }
         }
     } else {
-        let common_regs = pkgs
+        let common_regs = publishable_pkgs
             .iter()
             // `None` means "all registries", so drop them instead of including them
             // in the intersection.

tests/testsuite/package.rs

@@ -6227,19 +6227,41 @@ fn registry_inference_ignores_unpublishable() {
 
     p.cargo("package -Zpackage-workspace")
         .masquerade_as_nightly_cargo(&["package-workspace"])
-        .with_status(101)
         .with_stderr_data(str![[r#"
-[ERROR] conflicts between `package.publish` fields in the selected packages
+[PACKAGING] dep v0.1.0 ([ROOT]/foo/dep)
+[PACKAGED] 3 files, [FILE_SIZE]B ([FILE_SIZE]B compressed)
+[PACKAGING] main v0.0.1 ([ROOT]/foo/main)
+[UPDATING] `alternative` index
+[PACKAGED] 4 files, [FILE_SIZE]B ([FILE_SIZE]B compressed)
+[VERIFYING] dep v0.1.0 ([ROOT]/foo/dep)
+[COMPILING] dep v0.1.0 ([ROOT]/foo/target/package/dep-0.1.0)
+[FINISHED] `dev` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
+[VERIFYING] main v0.0.1 ([ROOT]/foo/main)
+[UPDATING] `alternative` index
+[UNPACKING] dep v0.1.0 (registry `[ROOT]/foo/target/package/tmp-registry`)
+[COMPILING] dep v0.1.0 (registry `alternative`)
+[COMPILING] main v0.0.1 ([ROOT]/foo/target/package/main-0.0.1)
+[FINISHED] `dev` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
 
 "#]])
         .run();
 
     p.cargo("package -Zpackage-workspace --registry=alternative")
         .masquerade_as_nightly_cargo(&["package-workspace"])
-        .with_status(101)
         .with_stderr_data(str![[r#"
-[ERROR] `main` cannot be packaged.
-The registry `alternative` is not listed in the `package.publish` value in Cargo.toml.
+[PACKAGING] dep v0.1.0 ([ROOT]/foo/dep)
+[PACKAGED] 3 files, [FILE_SIZE]B ([FILE_SIZE]B compressed)
+[PACKAGING] main v0.0.1 ([ROOT]/foo/main)
+[UPDATING] `alternative` index
+[PACKAGED] 4 files, [FILE_SIZE]B ([FILE_SIZE]B compressed)
+[VERIFYING] dep v0.1.0 ([ROOT]/foo/dep)
+[COMPILING] dep v0.1.0 ([ROOT]/foo/target/package/dep-0.1.0)
+[FINISHED] `dev` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
+[VERIFYING] main v0.0.1 ([ROOT]/foo/main)
+[UPDATING] `alternative` index
+[COMPILING] dep v0.1.0 (registry `alternative`)
+[COMPILING] main v0.0.1 ([ROOT]/foo/target/package/main-0.0.1)
+[FINISHED] `dev` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
 
 "#]])
         .run();
@@ -6464,7 +6486,16 @@ fn unpublishable_dependency() {
         .masquerade_as_nightly_cargo(&["package-workspace"])
         .with_status(101)
         .with_stderr_data(str![[r#"
-[ERROR] conflicts between `package.publish` fields in the selected packages
+[PACKAGING] dep v0.1.0 ([ROOT]/foo/dep)
+[PACKAGED] 3 files, [FILE_SIZE]B ([FILE_SIZE]B compressed)
+[PACKAGING] main v0.0.1 ([ROOT]/foo/main)
+[UPDATING] `alternative` index
+[ERROR] failed to prepare local package for uploading
+
+Caused by:
+  no matching package named `dep` found
+  location searched: registry `alternative`
+  required by package `main v0.0.1 ([ROOT]/foo/main)`
 
 "#]])
         .run();