Add handling for formatting `UnusableVersions` incompatibility

Cargo.lock

@@ -2229,7 +2229,7 @@ dependencies = [
 [[package]]
 name = "pubgrub"
 version = "0.2.1"
-source = "git+https://github.com/zanieb/pubgrub?rev=a1d584a5e506b8f0a600269373190c4a35b298d5#a1d584a5e506b8f0a600269373190c4a35b298d5"
+source = "git+https://github.com/zanieb/pubgrub?rev=92a14f37192aa5cc5d48efe901546c7f7b4810b7#92a14f37192aa5cc5d48efe901546c7f7b4810b7"
 dependencies = [
  "indexmap 2.1.0",
  "log",

Cargo.toml

@@ -51,7 +51,7 @@ once_cell = { version = "1.18.0" }
 petgraph = { version = "0.6.4" }
 platform-info = { version = "2.0.2" }
 plist = { version = "1.6.0" }
-pubgrub = { git = "https://github.com/zanieb/pubgrub", rev = "a1d584a5e506b8f0a600269373190c4a35b298d5" }
+pubgrub = { git = "https://github.com/zanieb/pubgrub", rev = "92a14f37192aa5cc5d48efe901546c7f7b4810b7" }
 pyo3 = { version = "0.20.0" }
 pyo3-log = { version = "0.9.0"}
 pyproject-toml = { version = "0.8.0" }

crates/puffin-resolver/src/pubgrub/report.rs

@@ -33,6 +33,25 @@ impl ReportFormatter<PubGrubPackage, Range<PubGrubVersion>> for PubGrubReportFor
                     format!("dependencies of {package} at version {set} are unavailable")
                 }
             }
+            External::UnusableVersions(package, set, reason) => {
+                if let Some(reason) = reason {
+                    if matches!(package, PubGrubPackage::Root(_)) {
+                        format!("{package} is unusable: {reason}")
+                    } else {
+                        if set == &Range::full() {
+                            format!("all versions of {package} are unusable: {reason}")
+                        } else {
+                            format!("{package}{set} is unusable: {reason}",)
+                        }
+                    }
+                } else {
+                    if set == &Range::full() {
+                        format!("all versions of {package} are unusable")
+                    } else {
+                        format!("{package}{set} is unusable")
+                    }
+                }
+            }
             External::UnusableDependencies(package, set, reason) => {
                 if let Some(reason) = reason {
                     if matches!(package, PubGrubPackage::Root(_)) {