devShell to eagerly evaluated?

[MangoIV]

to reproduce

• set basePackages = pkgs.haskell.packages.ghc90
• set devShell.enable = false

this should eval error:

error: haskell-language-server has dropped support for ghc 9.0 in version 2.4.0.0, please use a newer ghc version or an older nixpkgs version

I'm suspecting that there is some issue with the devShell being evaluated to eagerly; the package shouldn't depend on haskell-language-server and doesn't try to evaluate/ build it in all other projects

[roberth]

Can confirm. Here's a trace with hercules-ci-agent.

Trace

$ nix run nix/2.21-maintenance -- eval .#hercules-ci-agent.drvPath --show-trace --no-eval-cache
warning: Git tree '/home/user/h/hercules-ci-agent' is dirty
error:
       … while calling anonymous lambda
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/types.nix:593:29:
          592|       merge = loc: defs:
          593|         zipAttrsWith (name: defs:
             |                             ^
          594|           let merged = mergeDefinitions (loc ++ [name]) elemType defs;

       … while evaluating the attribute 'optionalValue.value'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:856:5:
          855|
          856|     optionalValue =
             |     ^
          857|       if isDefined then { value = mergedValue; }

       … while evaluating a branch condition
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:857:7:
          856|     optionalValue =
          857|       if isDefined then { value = mergedValue; }
             |       ^
          858|       else {};

       … while evaluating the attribute 'values'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:838:9:
          837|       in {
          838|         values = defs''';
             |         ^
          839|         inherit (defs'') highestPrio;

       … while evaluating a branch condition
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:834:11:
          833|           # Avoid sorting if we don't have to.
          834|           if any (def: def.value._type or "" == "order") defs''.values
             |           ^
          835|           then sortProperties defs''.values

       … while calling the 'any' builtin
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:834:14:
          833|           # Avoid sorting if we don't have to.
          834|           if any (def: def.value._type or "" == "order") defs''.values
             |              ^
          835|           then sortProperties defs''.values

       … while evaluating the attribute 'values'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:937:7:
          936|     in {
          937|       values = concatMap (def: if getPrio def == highestPrio then [(strip def)] else []) defs;
             |       ^
          938|       inherit highestPrio;

       … while calling the 'concatMap' builtin
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:937:16:
          936|     in {
          937|       values = concatMap (def: if getPrio def == highestPrio then [(strip def)] else []) defs;
             |                ^
          938|       inherit highestPrio;

       … while calling the 'concatMap' builtin
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:824:17:
          823|         # Process mkMerge and mkIf properties.
          824|         defs' = concatMap (m:
             |                 ^
          825|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))

       … while calling anonymous lambda
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:824:28:
          823|         # Process mkMerge and mkIf properties.
          824|         defs' = concatMap (m:
             |                            ^
          825|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))

       … while calling the 'map' builtin
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:825:11:
          824|         defs' = concatMap (m:
          825|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |           ^
          826|         ) defs;

       … while calling the 'addErrorContext' builtin
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:825:62:
          824|         defs' = concatMap (m:
          825|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |                                                              ^
          826|         ) defs;

       … while evaluating definitions from `/nix/store/5yhqhsl8x9xmhsy3ql8hi05c3zbnxx2x-source/modules/transposition.nix':

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:825:137:
          824|         defs' = concatMap (m:
          825|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |                                                                                                                                         ^
          826|         ) defs;

       … while calling 'dischargeProperties'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:896:25:
          895|   */
          896|   dischargeProperties = def:
             |                         ^
          897|     if def._type or "" == "merge" then

       … while evaluating a branch condition
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:897:5:
          896|   dischargeProperties = def:
          897|     if def._type or "" == "merge" then
             |     ^
          898|       concatMap dischargeProperties def.contents

       … while evaluating the attribute 'value'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/types.nix:599:58:
          598|         # Push down position info.
          599|         (map (def: mapAttrs (n: v: { inherit (def) file; value = v; }) def.value) defs);
             |                                                          ^
          600|       emptyValue = { value = {}; };

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/types.nix:599:58:
          598|         # Push down position info.
          599|         (map (def: mapAttrs (n: v: { inherit (def) file; value = v; }) def.value) defs);
             |                                                          ^
          600|       emptyValue = { value = {}; };

       (12 duplicate frames omitted)

       … while evaluating definitions from `/nix/store/g9np4n11jbvyqi2lqfy8ag4ffqayg293-source/flake.nix, via option perSystem':

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:825:137:
          824|         defs' = concatMap (m:
          825|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |                                                                                                                                         ^
          826|         ) defs;

       … while calling 'dischargeProperties'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:896:25:
          895|   */
          896|   dischargeProperties = def:
             |                         ^
          897|     if def._type or "" == "merge" then

       … while evaluating a branch condition
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:897:5:
          896|   dischargeProperties = def:
          897|     if def._type or "" == "merge" then
             |     ^
          898|       concatMap dischargeProperties def.contents

       … while evaluating the attribute 'value'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/types.nix:599:58:
          598|         # Push down position info.
          599|         (map (def: mapAttrs (n: v: { inherit (def) file; value = v; }) def.value) defs);
             |                                                          ^
          600|       emptyValue = { value = {}; };

       … from call site
         at /nix/store/g9np4n11jbvyqi2lqfy8ag4ffqayg293-source/flake.nix:465:44:
          464|               packages.hci = config.packages.hercules-ci-cli;
          465|               packages.hercules-ci-agent = config.packages.internal-hercules-ci-agent;
             |                                            ^
          466|

       (12 duplicate frames omitted)

       … while evaluating definitions from `/nix/store/dh7ji7jfgfys3j90cb2sihnyrv9ran0y-source/nix/modules/projects.nix':

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:825:137:
          824|         defs' = concatMap (m:
          825|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |                                                                                                                                         ^
          826|         ) defs;

       … while calling 'dischargeProperties'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:896:25:
          895|   */
          896|   dischargeProperties = def:
             |                         ^
          897|     if def._type or "" == "merge" then

       … while evaluating a branch condition
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:897:5:
          896|   dischargeProperties = def:
          897|     if def._type or "" == "merge" then
             |     ^
          898|       concatMap dischargeProperties def.contents

       … while evaluating the attribute 'value'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/types.nix:599:58:
          598|         # Push down position info.
          599|         (map (def: mapAttrs (n: v: { inherit (def) file; value = v; }) def.value) defs);
             |                                                          ^
          600|       emptyValue = { value = {}; };

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:633:36:
          632|     set:
          633|     listToAttrs (map (attr: f attr set.${attr}) (attrNames set));
             |                                    ^
          634|

       … while calling anonymous lambda
         at /nix/store/dh7ji7jfgfys3j90cb2sihnyrv9ran0y-source/nix/modules/projects.nix:44:45:
           43|               let
           44|                 packages = lib.mapAttrs (_: info: info.package) project.outputs.packages;
             |                                             ^
           45|               in

       … from call site
         at /nix/store/dh7ji7jfgfys3j90cb2sihnyrv9ran0y-source/nix/modules/projects.nix:44:51:
           43|               let
           44|                 packages = lib.mapAttrs (_: info: info.package) project.outputs.packages;
             |                                                   ^
           45|               in

       … while calling 'g'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:739:19:
          738|           g =
          739|             name: value:
             |                   ^
          740|             if isAttrs value && cond value

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:742:20:
          741|               then recurse (path ++ [name]) value
          742|               else f (path ++ [name]) value;
             |                    ^
          743|         in mapAttrs g;

       … while calling anonymous lambda
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:242:72:
          241|           # For definitions that have an associated option
          242|           declaredConfig = mapAttrsRecursiveCond (v: ! isOption v) (_: v: v.value) options;
             |                                                                        ^
          243|

       … while evaluating the attribute 'value'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:809:9:
          808|     in warnDeprecation opt //
          809|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
             |         ^
          810|         inherit (res.defsFinal') highestPrio;

       … while calling the 'addErrorContext' builtin
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:809:17:
          808|     in warnDeprecation opt //
          809|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
             |                 ^
          810|         inherit (res.defsFinal') highestPrio;

       … while evaluating the option `perSystem.x86_64-linux.haskellProjects.internal.outputs.packages.hercules-ci-agent.package':

       … while evaluating the attribute 'mergedValue'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:844:5:
          843|     # Type-check the remaining definitions, and merge them. Or throw if no definitions.
          844|     mergedValue =
             |     ^
          845|       if isDefined then

       … while evaluating a branch condition
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:845:7:
          844|     mergedValue =
          845|       if isDefined then
             |       ^
          846|         if all (def: type.check def.value) defsFinal then type.merge loc defsFinal

       (9 duplicate frames omitted)

       … while evaluating definitions from `/nix/store/dh7ji7jfgfys3j90cb2sihnyrv9ran0y-source/nix/modules/project.nix':

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:825:137:
          824|         defs' = concatMap (m:
          825|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |                                                                                                                                         ^
          826|         ) defs;

       … while calling 'dischargeProperties'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:896:25:
          895|   */
          896|   dischargeProperties = def:
             |                         ^
          897|     if def._type or "" == "merge" then

       … while evaluating a branch condition
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:897:5:
          896|   dischargeProperties = def:
          897|     if def._type or "" == "merge" then
             |     ^
          898|       concatMap dischargeProperties def.contents

       … while evaluating the attribute 'value'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:607:53:
          606|                 (n: value:
          607|                   [{ inherit (module) file; inherit value; }]
             |                                                     ^
          608|                 )

       … from call site
         at /nix/store/dh7ji7jfgfys3j90cb2sihnyrv9ran0y-source/nix/modules/project.nix:182:32:
          181|     let
          182|       inherit (config.outputs) finalPackages packages;
             |                                ^
          183|

       … while calling 'g'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:739:19:
          738|           g =
          739|             name: value:
             |                   ^
          740|             if isAttrs value && cond value

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:742:20:
          741|               then recurse (path ++ [name]) value
          742|               else f (path ++ [name]) value;
             |                    ^
          743|         in mapAttrs g;

       … while calling anonymous lambda
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:242:72:
          241|           # For definitions that have an associated option
          242|           declaredConfig = mapAttrsRecursiveCond (v: ! isOption v) (_: v: v.value) options;
             |                                                                        ^
          243|

       … while evaluating the attribute 'value'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:809:9:
          808|     in warnDeprecation opt //
          809|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
             |         ^
          810|         inherit (res.defsFinal') highestPrio;

       … while calling the 'addErrorContext' builtin
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:809:17:
          808|     in warnDeprecation opt //
          809|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
             |                 ^
          810|         inherit (res.defsFinal') highestPrio;

       … while evaluating the option `perSystem.x86_64-linux.haskellProjects.internal.outputs.finalPackages':

       (16 duplicate frames omitted)

       … from call site
         at /nix/store/dh7ji7jfgfys3j90cb2sihnyrv9ran0y-source/nix/modules/project.nix:234:25:
          233|
          234|         finalPackages = config.basePackages.extend finalOverlay;
             |                         ^
          235|

       … while calling 'g'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:739:19:
          738|           g =
          739|             name: value:
             |                   ^
          740|             if isAttrs value && cond value

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:742:20:
          741|               then recurse (path ++ [name]) value
          742|               else f (path ++ [name]) value;
             |                    ^
          743|         in mapAttrs g;

       … while calling anonymous lambda
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:242:72:
          241|           # For definitions that have an associated option
          242|           declaredConfig = mapAttrsRecursiveCond (v: ! isOption v) (_: v: v.value) options;
             |                                                                        ^
          243|

       … while evaluating the attribute 'value'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:809:9:
          808|     in warnDeprecation opt //
          809|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
             |         ^
          810|         inherit (res.defsFinal') highestPrio;

       … while calling the 'addErrorContext' builtin
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:809:17:
          808|     in warnDeprecation opt //
          809|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
             |                 ^
          810|         inherit (res.defsFinal') highestPrio;

       … while evaluating the option `perSystem.x86_64-linux.haskellProjects.internal.basePackages':

       … while evaluating the attribute 'mergedValue'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:844:5:
          843|     # Type-check the remaining definitions, and merge them. Or throw if no definitions.
          844|     mergedValue =
             |     ^
          845|       if isDefined then

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:846:59:
          845|       if isDefined then
          846|         if all (def: type.check def.value) defsFinal then type.merge loc defsFinal
             |                                                           ^
          847|         else let allInvalid = filter (def: ! type.check def.value) defsFinal;

       … while calling 'merge'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/types.nix:568:20:
          567|       check = isAttrs;
          568|       merge = loc: defs:
             |                    ^
          569|         mapAttrs (n: v: v.value) (filterAttrs (n: v: v ? value) (zipAttrsWith (name: defs:

       … while calling the 'mapAttrs' builtin
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/types.nix:569:9:
          568|       merge = loc: defs:
          569|         mapAttrs (n: v: v.value) (filterAttrs (n: v: v ? value) (zipAttrsWith (name: defs:
             |         ^
          570|             (mergeDefinitions (loc ++ [name]) elemType defs).optionalValue

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/types.nix:569:35:
          568|       merge = loc: defs:
          569|         mapAttrs (n: v: v.value) (filterAttrs (n: v: v ? value) (zipAttrsWith (name: defs:
             |                                   ^
          570|             (mergeDefinitions (loc ++ [name]) elemType defs).optionalValue

       … while calling 'filterAttrs'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:419:5:
          418|     # The attribute set to filter
          419|     set:
             |     ^
          420|     listToAttrs (concatMap (name: let v = set.${name}; in if pred name v then [(nameValuePair name v)] else []) (attrNames set));

       … while calling the 'listToAttrs' builtin
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:420:5:
          419|     set:
          420|     listToAttrs (concatMap (name: let v = set.${name}; in if pred name v then [(nameValuePair name v)] else []) (attrNames set));
             |     ^
          421|

       … while calling the 'concatMap' builtin
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:420:18:
          419|     set:
          420|     listToAttrs (concatMap (name: let v = set.${name}; in if pred name v then [(nameValuePair name v)] else []) (attrNames set));
             |                  ^
          421|

       … while calling anonymous lambda
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:420:29:
          419|     set:
          420|     listToAttrs (concatMap (name: let v = set.${name}; in if pred name v then [(nameValuePair name v)] else []) (attrNames set));
             |                             ^
          421|

       … while evaluating a branch condition
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:420:59:
          419|     set:
          420|     listToAttrs (concatMap (name: let v = set.${name}; in if pred name v then [(nameValuePair name v)] else []) (attrNames set));
             |                                                           ^
          421|

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:420:62:
          419|     set:
          420|     listToAttrs (concatMap (name: let v = set.${name}; in if pred name v then [(nameValuePair name v)] else []) (attrNames set));
             |                                                              ^
          421|

       … while calling anonymous lambda
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/types.nix:569:51:
          568|       merge = loc: defs:
          569|         mapAttrs (n: v: v.value) (filterAttrs (n: v: v ? value) (zipAttrsWith (name: defs:
             |                                                   ^
          570|             (mergeDefinitions (loc ++ [name]) elemType defs).optionalValue

       … from call site
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/attrsets.nix:420:43:
          419|     set:
          420|     listToAttrs (concatMap (name: let v = set.${name}; in if pred name v then [(nameValuePair name v)] else []) (attrNames set));
             |                                           ^
          421|

       … while calling anonymous lambda
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/types.nix:569:86:
          568|       merge = loc: defs:
          569|         mapAttrs (n: v: v.value) (filterAttrs (n: v: v ? value) (zipAttrsWith (name: defs:
             |                                                                                      ^
          570|             (mergeDefinitions (loc ++ [name]) elemType defs).optionalValue

       … while evaluating the attribute 'optionalValue'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/modules.nix:856:5:
          855|
          856|     optionalValue =
             |     ^
          857|       if isDefined then { value = mergedValue; }

       (14 duplicate frames omitted)

       … while evaluating the attribute 'value'
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/lib/types.nix:573:60:
          572|           # Push down position info.
          573|           (map (def: mapAttrs (n: v: { inherit (def) file; value = v; }) def.value) defs)));
             |                                                            ^
          574|       emptyValue = { value = {}; };

       … while calling the 'throw' builtin
         at /nix/store/2p9qcybzmx1rfayjw866rz8xljbw45g9-source/pkgs/development/haskell-modules/configuration-ghc-9.0.x.nix:79:30:
           78|
           79|   haskell-language-server =  throw "haskell-language-server has dropped support for ghc 9.0 in version 2.4.0.0, please use a newer ghc version or an older nixpkgs version";
             |                              ^
           80|

       error: haskell-language-server has dropped support for ghc 9.0 in version 2.4.0.0, please use a newer ghc version or an older nixpkgs version

The culprit is types.attrsOf, which supports mkIf and therefore has to perform a filterAttrs based on the attribute values, making it too strict.

Expect an eval performance boost when this is fixed.

[srid]

Does that PR fix it? Because devShell.tools already uses typs.lazyAttrsOf.

haskell-flake/nix/modules/project/devshell.nix

Lines 19 to 20 in 938888c

	tools = mkOption {
	type = functionTo (types.lazyAttrsOf (types.nullOr types.package));

[roberth]

I've tried hercules-ci-agent, but got stuck migrating away from its haskell overlay

• Modular overrides #162 (comment).

[roberth]

devShell.tools already uses typs.lazyAttrsOf.

According to the trace I got from the haskell-flake example/, the culprit was basePackages, which was fixed by the PR.
I don't know @MangoIV's project though.

[MangoIV]

jup, worked for me, thank you @roberth <3