`attribute 'extend' missing` error when running nix develop

nix.trace

warning: Git tree '/home/user/hs/web/mdn-local-library-tutorial' is dirty
error: attribute 'extend' missing

       at /nix/store/k066hn412qjzs933n8dk8xqsnpqhj1sb-source/nix/modules/project/outputs.nix:91:23:

           90|
           91|       finalPackages = config.basePackages.extend finalOverlay;
             |                       ^
           92|

       … while evaluating the attribute 'value'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:605:52:

          604|                 (n: value:
          605|                   [{ inherit (module) file; inherit value; }]
             |                                                    ^
          606|                 )

       … while evaluating 'dischargeProperties'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:894:25:

          893|   */
          894|   dischargeProperties = def:
             |                         ^
          895|     if def._type or "" == "merge" then

       … from call site

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:823:137:

          822|         defs' = concatMap (m:
          823|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |                                                                                                                                         ^
          824|         ) defs;

       … while evaluating definitions from `/nix/store/k066hn412qjzs933n8dk8xqsnpqhj1sb-source/nix/modules/project/outputs.nix':

       … while evaluating anonymous lambda

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:822:28:

          821|         # Process mkMerge and mkIf properties.
          822|         defs' = concatMap (m:
             |                            ^
          823|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))

       … from call site

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:822:17:

          821|         # Process mkMerge and mkIf properties.
          822|         defs' = concatMap (m:
             |                 ^
          823|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))

       … while evaluating the attribute 'values'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:935:7:

          934|     in {
          935|       values = concatMap (def: if getPrio def == highestPrio then [(strip def)] else []) defs;
             |       ^
          936|       inherit highestPrio;

       … while evaluating the attribute 'values'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:836:9:

          835|       in {
          836|         values = defs''';
             |         ^
          837|         inherit (defs'') highestPrio;

       … while evaluating the attribute 'mergedValue'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:842:5:

          841|     # Type-check the remaining definitions, and merge them. Or throw if no definitions.
          842|     mergedValue =
             |     ^
          843|       if isDefined then

       … while evaluating the option `perSystem.x86_64-linux.haskellProjects.ghc865.outputs.finalPackages':

       … while evaluating the attribute 'value'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:807:9:

          806|     in warnDeprecation opt //
          807|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
             |         ^
          808|         inherit (res.defsFinal') highestPrio;

       … while evaluating anonymous lambda

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-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|

       … from call site

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/attrsets.nix:632:20:

          631|               then recurse (path ++ [name]) value
          632|               else f (path ++ [name]) value;
             |                    ^
          633|         in mapAttrs g;

       … while evaluating 'g'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/attrsets.nix:629:19:

          628|           g =
          629|             name: value:
             |                   ^
          630|             if isAttrs value && cond value

       … from call site

       … while evaluating the attribute 'value'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:605:52:

          604|                 (n: value:
          605|                   [{ inherit (module) file; inherit value; }]
             |                                                    ^
          606|                 )

       … while evaluating 'dischargeProperties'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:894:25:

          893|   */
          894|   dischargeProperties = def:
             |                         ^
          895|     if def._type or "" == "merge" then

       … from call site

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:823:137:

          822|         defs' = concatMap (m:
          823|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |                                                                                                                                         ^
          824|         ) defs;

       … while evaluating definitions from `/nix/store/19jfhx6d82dvn5fyr0sbh2l87wf4f1cp-source/flake.nix, via option perSystem':

       … while evaluating anonymous lambda

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:822:28:

          821|         # Process mkMerge and mkIf properties.
          822|         defs' = concatMap (m:
             |                            ^
          823|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))

       … from call site

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:822:17:

          821|         # Process mkMerge and mkIf properties.
          822|         defs' = concatMap (m:
             |                 ^
          823|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))

       … while evaluating the attribute 'values'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:935:7:

          934|     in {
          935|       values = concatMap (def: if getPrio def == highestPrio then [(strip def)] else []) defs;
             |       ^
          936|       inherit highestPrio;

       … while evaluating the attribute 'values'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:836:9:

          835|       in {
          836|         values = defs''';
             |         ^
          837|         inherit (defs'') highestPrio;

       … while evaluating the attribute 'mergedValue'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:842:5:

          841|     # Type-check the remaining definitions, and merge them. Or throw if no definitions.
          842|     mergedValue =
             |     ^
          843|       if isDefined then

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

       … while evaluating the attribute 'value'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:807:9:

          806|     in warnDeprecation opt //
          807|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
             |         ^
          808|         inherit (res.defsFinal') highestPrio;

       … while evaluating anonymous lambda

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-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|

       … from call site

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/attrsets.nix:632:20:

          631|               then recurse (path ++ [name]) value
          632|               else f (path ++ [name]) value;
             |                    ^
          633|         in mapAttrs g;

       … while evaluating 'g'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/attrsets.nix:629:19:

          628|           g =
          629|             name: value:
             |                   ^
          630|             if isAttrs value && cond value

       … from call site

       … while evaluating the attribute 'value'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:605:52:

          604|                 (n: value:
          605|                   [{ inherit (module) file; inherit value; }]
             |                                                    ^
          606|                 )

       … while evaluating 'dischargeProperties'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:894:25:

          893|   */
          894|   dischargeProperties = def:
             |                         ^
          895|     if def._type or "" == "merge" then

       … from call site

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:823:137:

          822|         defs' = concatMap (m:
          823|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |                                                                                                                                         ^
          824|         ) defs;

       … while evaluating definitions from `/nix/store/k066hn412qjzs933n8dk8xqsnpqhj1sb-source/nix/modules/project/outputs.nix':

       … while evaluating anonymous lambda

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:822:28:

          821|         # Process mkMerge and mkIf properties.
          822|         defs' = concatMap (m:
             |                            ^
          823|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))

       … from call site

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:822:17:

          821|         # Process mkMerge and mkIf properties.
          822|         defs' = concatMap (m:
             |                 ^
          823|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))

       … while evaluating the attribute 'values'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:935:7:

          934|     in {
          935|       values = concatMap (def: if getPrio def == highestPrio then [(strip def)] else []) defs;
             |       ^
          936|       inherit highestPrio;

       … while evaluating the attribute 'values'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:836:9:

          835|       in {
          836|         values = defs''';
             |         ^
          837|         inherit (defs'') highestPrio;

       … while evaluating the attribute 'mergedValue'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:842:5:

          841|     # Type-check the remaining definitions, and merge them. Or throw if no definitions.
          842|     mergedValue =
             |     ^
          843|       if isDefined then

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

       … while evaluating the attribute 'value'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:807:9:

          806|     in warnDeprecation opt //
          807|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
             |         ^
          808|         inherit (res.defsFinal') highestPrio;

       … while evaluating anonymous lambda

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-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|

       … from call site

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/attrsets.nix:632:20:

          631|               then recurse (path ++ [name]) value
          632|               else f (path ++ [name]) value;
             |                    ^
          633|         in mapAttrs g;

       … while evaluating 'g'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/attrsets.nix:629:19:

          628|           g =
          629|             name: value:
             |                   ^
          630|             if isAttrs value && cond value

       … from call site

       … while evaluating the attribute 'value'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:605:52:

          604|                 (n: value:
          605|                   [{ inherit (module) file; inherit value; }]
             |                                                    ^
          606|                 )

       … while evaluating 'dischargeProperties'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:894:25:

          893|   */
          894|   dischargeProperties = def:
             |                         ^
          895|     if def._type or "" == "merge" then

       … from call site

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:823:137:

          822|         defs' = concatMap (m:
          823|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |                                                                                                                                         ^
          824|         ) defs;

       … while evaluating definitions from `/nix/store/k066hn412qjzs933n8dk8xqsnpqhj1sb-source/nix/modules/project/devshell.nix':

       … while evaluating anonymous lambda

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:822:28:

          821|         # Process mkMerge and mkIf properties.
          822|         defs' = concatMap (m:
             |                            ^
          823|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))

       … from call site

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:822:17:

          821|         # Process mkMerge and mkIf properties.
          822|         defs' = concatMap (m:
             |                 ^
          823|           map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))

       … while evaluating the attribute 'values'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:935:7:

          934|     in {
          935|       values = concatMap (def: if getPrio def == highestPrio then [(strip def)] else []) defs;
             |       ^
          936|       inherit highestPrio;

       … while evaluating the attribute 'values'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:836:9:

          835|       in {
          836|         values = defs''';
             |         ^
          837|         inherit (defs'') highestPrio;

       … while evaluating the attribute 'mergedValue'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:842:5:

          841|     # Type-check the remaining definitions, and merge them. Or throw if no definitions.
          842|     mergedValue =
             |     ^
          843|       if isDefined then

       … while evaluating the option `perSystem.x86_64-linux.haskellProjects.default.outputs.devShell':

       … while evaluating the attribute 'value'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/modules.nix:807:9:

          806|     in warnDeprecation opt //
          807|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
             |         ^
          808|         inherit (res.defsFinal') highestPrio;

       … while evaluating anonymous lambda

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-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|

       … from call site

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/attrsets.nix:632:20:

          631|               then recurse (path ++ [name]) value
          632|               else f (path ++ [name]) value;
             |                    ^
          633|         in mapAttrs g;

       … while evaluating 'g'

       at /nix/store/z6w242l49pbrdawkz5vdhfxh2mvsj36c-source/lib/attrsets.nix:629:19:

          628|           g =
          629|             name: value:
             |                   ^
          630|             if isAttrs value && cond value

       … from call site

       … while evaluating 'flatten'

       at /nix/store/mj0hy52z22q5gpsf33akndxiclxd8ray-source/lib/lists.nix:186:13:

          185|   */
          186|   flatten = x:
             |             ^
          187|     if isList x

       … from call site

       at /nix/store/mj0hy52z22q5gpsf33akndxiclxd8ray-source/pkgs/build-support/mkshell/default.nix:19:36:

           18|     (attrs.${name} or [ ]) ++
           19|     (lib.subtractLists inputsFrom (lib.flatten (lib.catAttrs name inputsFrom)));
             |                                    ^
           20|

       … while evaluating 'mergeInputs'

       at /nix/store/mj0hy52z22q5gpsf33akndxiclxd8ray-source/pkgs/build-support/mkshell/default.nix:17:17:

           16| let
           17|   mergeInputs = name:
             |                 ^
           18|     (attrs.${name} or [ ]) ++

       … from call site

       at /nix/store/mj0hy52z22q5gpsf33akndxiclxd8ray-source/pkgs/build-support/mkshell/default.nix:36:17:

           35|
           36|   buildInputs = mergeInputs "buildInputs";
             |                 ^
           37|   nativeBuildInputs = packages ++ (mergeInputs "nativeBuildInputs");

       … while evaluating 'imap1'

       at /nix/store/mj0hy52z22q5gpsf33akndxiclxd8ray-source/lib/lists.nix:165:14:

          164|   */
          165|   imap1 = f: list: genList (n: f (n + 1) (elemAt list n)) (length list);
             |              ^
          166|

       … from call site

       at /nix/store/mj0hy52z22q5gpsf33akndxiclxd8ray-source/lib/trivial.nix:138:19:

          137|   */
          138|   flip = f: a: b: f b a;
             |                   ^
          139|

       … while evaluating 'flip'

       at /nix/store/mj0hy52z22q5gpsf33akndxiclxd8ray-source/lib/trivial.nix:138:16:

          137|   */
          138|   flip = f: a: b: f b a;
             |                ^
          139|

       … from call site

       at /nix/store/mj0hy52z22q5gpsf33akndxiclxd8ray-source/pkgs/stdenv/generic/make-derivation.nix:224:49:

          223|   checkDependencyList = checkDependencyList' [];
          224|   checkDependencyList' = positions: name: deps: lib.flip lib.imap1 deps (index: dep:
             |                                                 ^
          225|     if lib.isDerivation dep || dep == null || builtins.isString dep || builtins.isPath dep then dep

       … while evaluating 'checkDependencyList''

       at /nix/store/mj0hy52z22q5gpsf33akndxiclxd8ray-source/pkgs/stdenv/generic/make-derivation.nix:224:43:

          223|   checkDependencyList = checkDependencyList' [];
          224|   checkDependencyList' = positions: name: deps: lib.flip lib.imap1 deps (index: dep:
             |                                           ^
          225|     if lib.isDerivation dep || dep == null || builtins.isString dep || builtins.isPath dep then dep

       … from call site

       at /nix/store/mj0hy52z22q5gpsf33akndxiclxd8ray-source/pkgs/stdenv/generic/make-derivation.nix:257:52:

          256|       (map (drv: drv.__spliced.hostHost or drv) (checkDependencyList "depsHostHost" depsHostHost))
          257|       (map (drv: drv.__spliced.hostTarget or drv) (checkDependencyList "buildInputs" buildInputs'))
             |                                                    ^
          258|     ]

       … while evaluating 'chooseDevOutputs'

       at /nix/store/mj0hy52z22q5gpsf33akndxiclxd8ray-source/lib/attrsets.nix:1025:5:

         1024|     # List of packages to pick `dev` outputs from
         1025|     drvs:
             |     ^
         1026|     builtins.map getDev drvs;

       … from call site

       … while evaluating the attribute 'buildInputs' of the derivation 'nix-shell'

       at /nix/store/mj0hy52z22q5gpsf33akndxiclxd8ray-source/pkgs/stdenv/generic/make-derivation.nix:311:7:

          310|     // (lib.optionalAttrs (attrs ? name || (attrs ? pname && attrs ? version)) {
          311|       name =
             |       ^
          312|         let