tests.nixpkgs-check-by-name: Deterministic ordering

Makes errors for attributes deterministic so it's easier to test (also,
reproducibility is always nice)

pkgs/test/nixpkgs-check-by-name/src/eval.nix

@@ -76,14 +76,15 @@ let
         };
       };
 
-  attrInfos = builtins.listToAttrs (map (name: {
-    inherit name;
-    value =
+  attrInfos = map (name: [
+    name
+    (
       if ! pkgs ? ${name} then
         { Missing = null; }
       else
-        { Existing = attrInfo name pkgs.${name}; };
-  }) attrs);
+        { Existing = attrInfo name pkgs.${name}; }
+    )
+  ]) attrs;
 
 in
 attrInfos

pkgs/test/nixpkgs-check-by-name/src/eval.rs

@@ -6,7 +6,6 @@ use std::path::Path;
 
 use anyhow::Context;
 use serde::Deserialize;
-use std::collections::HashMap;
 use std::path::PathBuf;
 use std::process;
 use tempfile::NamedTempFile;
@@ -119,7 +118,7 @@ pub fn check_values(
         anyhow::bail!("Failed to run command {command:?}");
     }
     // Parse the resulting JSON value
-    let attributes: HashMap<String, ByNameAttribute> = serde_json::from_slice(&result.stdout)
+    let attributes: Vec<(String, ByNameAttribute)> = serde_json::from_slice(&result.stdout)
         .context(format!(
             "Failed to deserialise {}",
             String::from_utf8_lossy(&result.stdout)
@@ -201,6 +200,7 @@ pub fn check_values(
     ));
 
     Ok(check_result.map(|elems| ratchet::Nixpkgs {
-        packages: elems.into_iter().collect(),
+        package_names,
+        package_map: elems.into_iter().collect(),
     }))
 }

pkgs/test/nixpkgs-check-by-name/src/ratchet.rs

@@ -10,8 +10,10 @@ use std::collections::HashMap;
 /// The ratchet value for the entirety of Nixpkgs.
 #[derive(Default)]
 pub struct Nixpkgs {
-    /// The ratchet values for each package in `pkgs/by-name`
-    pub packages: HashMap<String, Package>,
+    /// Sorted list of attributes in package_map
+    pub package_names: Vec<String>,
+    /// The ratchet values for all packages
+    pub package_map: HashMap<String, Package>,
 }
 
 impl Nixpkgs {
@@ -20,9 +22,9 @@ impl Nixpkgs {
         validation::sequence_(
             // We only loop over the current attributes,
             // we don't need to check ones that were removed
-            to.packages
-                .into_iter()
-                .map(|(name, attr_to)| Package::compare(&name, from.packages.get(&name), &attr_to)),
+            to.package_names.into_iter().map(|name| {
+                Package::compare(&name, from.package_map.get(&name), &to.package_map[&name])
+            }),
         )
     }
 }