diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,8 +5,17 @@
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## Unreleased
 
+## [0.9.9] - 2022-12-02
+
+### Fixed
+
+ - The flake `templates` check now allows filtered sources.
+
+ - Tweaks to diagnostic messages
+
+## [0.9.8] - 2022-11-15
+
 ### Added
 
  - `herculesCI.onSchedule` jobs, which a created at set times. These can be used
@@ -632,6 +641,7 @@
 
 - Initial release
 
+[0.9.8]: https://github.com/hercules-ci/hercules-ci-agent/compare/hercules-ci-agent-0.9.7...hercules-ci-agent-0.9.8
 [0.9.7]: https://github.com/hercules-ci/hercules-ci-agent/compare/hercules-ci-agent-0.9.6...hercules-ci-agent-0.9.7
 [0.9.6]: https://github.com/hercules-ci/hercules-ci-agent/compare/hercules-ci-agent-0.9.5...hercules-ci-agent-0.9.6
 [0.9.5]: https://github.com/hercules-ci/hercules-ci-agent/compare/hercules-ci-agent-0.9.3...hercules-ci-agent-0.9.5
diff --git a/data/default-herculesCI-for-flake.nix b/data/default-herculesCI-for-flake.nix
--- a/data/default-herculesCI-for-flake.nix
+++ b/data/default-herculesCI-for-flake.nix
@@ -11,6 +11,7 @@
     intersectAttrs
     listToAttrs
     mapAttrs
+    typeOf
     ;
 
   # lib
@@ -115,6 +116,41 @@
     then throw "Attribute is not a shell derivation"
     else drv // { buildDependenciesOnly = true; };
 
+  hasPrefix = pre: s: builtins.substring 0 (builtins.stringLength pre) s == pre;
+
+  stringIsStorePath = s: hasPrefix builtins.storeDir (dirOf s);
+
+  isPathLike =
+    v: (builtins.typeOf v == "path" && stringIsStorePath (toString v))
+      || (builtins.typeOf v == "string" && stringIsStorePath v)
+      || (v?__toString && isPathLike (v.__toString v))
+      || (v?outPath && isPathLike v.outPath);
+
+  checkTemplate = name: template:
+    if !builtins.isAttrs template
+    then throw "Template `templates.${name}` is not an attribute set."
+
+    else if !template?description
+    then throw "Template `templates.${name}` does not have a `description` string attribute."
+
+    else if typeOf template.description != "string"
+    then throw "`templates.${name}.description` must be a string, but its type is ${typeOf template.description}."
+
+    else if !template?path
+    then throw "Template `templates.${name}` does not have a `path` attribute."
+
+    else if !isPathLike template.path
+    then
+      if builtins.typeOf template.path == "string" ||
+        builtins.typeOf template.path == "path"
+      then throw "`templates.${name}.path` must be a path value in the store, or a string representing a store path, or an attribute set coercible to such values (e.g. cleanSource return value). However, the value is ${toString template.path}"
+      else throw "`templates.${name}.path` must be a path value in the store, or a string representing a store path, or an attribute set coercible to such values (e.g. cleanSource return value). However, the type is ${builtins.typeOf template.path}"
+
+    else if !(builtins.pathExists template.path)
+    then throw "Template path `templates.${name}.path` points to a location that does not exist."
+
+    else template;
+
   translations =
     let
       ignore = args: x: null;
@@ -131,17 +167,7 @@
       nixosConfigurations = args: attrs: mapAttrs (k: sys: { config.system.build.toplevel = sys.config.system.build.toplevel; }) (filterSystemConfigs args.ciSystems attrs);
       darwinConfigurations = args: attrs: mapAttrs (k: sys: { config.system.build.toplevel = sys.config.system.build.toplevel; }) (filterSystemConfigs args.ciSystems attrs);
       formatter = forSystems (sys: formatter: formatter);
-      templates = args: attrs: mapAttrs
-        (name: template:
-          if builtins.typeOf (template.description or null) != "string"
-          then throw "Template `templates.${name}` does not have a `description` string attribute."
-          else if builtins.typeOf template.path != "path"
-          then throw "Template `templates.${name}` does not have a `path` attribute, containing a path value."
-          else if !(builtins.pathExists template.path)
-          then throw "Template path `templates.${name}.path` points to a directory that does not exist."
-          else template
-        )
-        attrs;
+      templates = args: attrs: mapAttrs checkTemplate attrs;
 
       effects = args: effects:
         if builtins.isAttrs effects
diff --git a/hercules-ci-agent.cabal b/hercules-ci-agent.cabal
--- a/hercules-ci-agent.cabal
+++ b/hercules-ci-agent.cabal
@@ -1,7 +1,7 @@
 cabal-version: 2.4
 
 name:           hercules-ci-agent
-version:        0.9.8
+version:        0.9.9
 synopsis:       Runs Continuous Integration tasks on your machines
 category:       Nix, CI, Testing, DevOps
 homepage:       https://docs.hercules-ci.com
diff --git a/hercules-ci-agent/Hercules/Agent.hs b/hercules-ci-agent/Hercules/Agent.hs
--- a/hercules-ci-agent/Hercules/Agent.hs
+++ b/hercules-ci-agent/Hercules/Agent.hs
@@ -100,7 +100,7 @@
 configChecks = do
   trusted <- asks (Config.nixUserIsTrusted . Env.config)
   when (not trusted) do
-    logLocM WarningS "Your config does not indicate you have set up your user as a trusted user on the system. Running the agent as a trusted user ensures that your cache configuration is compatible with the system and improves performance if you have more than one agent. The NixOS and nix-darwin modules should configure this automatically. If this agent was set up with a manually written config file, see https://docs.hercules-ci.com/hercules-ci/reference/agent-config/"
+    logLocM WarningS "Your config does not indicate you have set up the user that runs the agent as a trusted-user on the system. Running the agent as a trusted-user ensures that your cache configuration is compatible with the system and it improves performance. The NixOS and nix-darwin modules configure this automatically. If this agent was set up with a manually written config file, add the user that runs the agent to nix.settings.trusted-users in your system configuration, or add it to the trusted-users line in your system nix.conf."
 
 run :: Env.Env -> Config.FinalConfig -> IO ()
 run env _cfg = do
diff --git a/hercules-ci-agent/Hercules/Agent/Nix/Init.hs b/hercules-ci-agent/Hercules/Agent/Nix/Init.hs
--- a/hercules-ci-agent/Hercules/Agent/Nix/Init.hs
+++ b/hercules-ci-agent/Hercules/Agent/Nix/Init.hs
@@ -7,23 +7,25 @@
 newEnv :: IO Env
 newEnv = do
   nixInfo <- EnvironmentInfo.getNixInfo
-  print nixInfo
   when (EnvironmentInfo.nixNarinfoCacheNegativeTTL nixInfo /= 0) $ do
     putErrText
       "\n\
-      \We have detected that the setting narinfo-cache-negative-ttl is non-zero.\n\
+      \We have detected that the Nix setting narinfo-cache-negative-ttl is non-zero.\n\
       \Running hercules-ci-agent on a system with a non-zero negative ttl will cause\n\
       \problems when run in a cluster.\n\
       \Note that this setting only affects the caching of paths that are *missing*\n\
       \from a cache. Paths that *are* in the binary cache are cached as configured in\n\
-      \the 'positive' option.\n\
+      \the narinfo-cache-positive-ttl option. You don't need to configure the positive\n\
+      \option. \n\
       \\n\
       \On NixOS and nix-darwin, use the recommended installation method via module,\n\
       \make sure that the `narinfo-cache-negative-ttl` isn't set via other means.\n\
       \If you can't use the module, use\
+      \    nix.settings.narinfo-cache-negative-ttl = 0;\n\
+      \  or\n\
       \    nix.extraOptions = \"narinfo-cache-negative-ttl = 0\"\n\
       \\n\
-      \or add to your system nix.conf:\n\
+      \or add to your system /etc/nix/nix.conf:\n\
       \    narinfo-cache-negative-ttl = 0\n\
       \n"
     throwIO $ FatalError "Please configure your system's Nix with:  narinfo-cache-negative-ttl = 0  "