Ignore self requirements (#233)

gps3 0.33.3 depends on itself, which we can ignore. I've also added the
home assistant requirements since it occurred when testing with this.

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

@@ -1,6 +1,7 @@
 use anyhow::Result;
 use itertools::Itertools;
 use pubgrub::range::Range;
+use tracing::warn;
 
 use pep508_rs::{MarkerEnvironment, Requirement};
 use puffin_package::dist_info_name::DistInfoName;
@@ -20,9 +21,20 @@ mod version;
 pub(crate) fn iter_requirements<'a>(
     requirements: impl Iterator<Item = &'a Requirement> + 'a,
     extra: Option<&'a DistInfoName>,
+    source: Option<&'a PackageName>,
     env: &'a MarkerEnvironment,
 ) -> impl Iterator<Item = (PubGrubPackage, Range<PubGrubVersion>)> + 'a {
     requirements
+        .filter(move |requirement| {
+            let normalized = PackageName::normalize(&requirement.name);
+            if source.is_some_and(|source| source == &normalized) {
+                // TODO: Warn only once here
+                warn!("{} depends on itself", normalized);
+                false
+            } else {
+                true
+            }
+        })
         .filter(move |requirement| {
             // TODO(charlie): We shouldn't need a vector here.
             let extra = if let Some(extra) = extra {

crates/puffin-resolver/src/resolver.rs

@@ -390,7 +390,7 @@ impl<'a, Context: BuildContext + Sync> Resolver<'a, Context> {
 
                 // Add the root requirements.
                 for (package, version) in
-                    iter_requirements(self.requirements.iter(), None, self.markers)
+                    iter_requirements(self.requirements.iter(), None, None, self.markers)
                 {
                     // Emit a request to fetch the metadata for this package.
                     if let PubGrubPackage::Package(package_name, None) = &package {
@@ -443,9 +443,12 @@ impl<'a, Context: BuildContext + Sync> Resolver<'a, Context> {
                 let mut constraints =
                     DependencyConstraints::<PubGrubPackage, Range<PubGrubVersion>>::default();
 
-                for (package, version) in
+                for (package, version) in iter_requirements(
-                    iter_requirements(metadata.requires_dist.iter(), extra.as_ref(), self.markers)
+                    metadata.requires_dist.iter(),
-                {
+                    extra.as_ref(),
+                    Some(package_name),
+                    self.markers,
+                ) {
                     debug!("Adding transitive dependency: {package} {version}");
 
                     // Emit a request to fetch the metadata for this package.