diff --git a/doc/languages-frameworks/javascript.section.md b/doc/languages-frameworks/javascript.section.md
index 925662592b04..9fb6ea662746 100644
--- a/doc/languages-frameworks/javascript.section.md
+++ b/doc/languages-frameworks/javascript.section.md
@@ -513,10 +513,10 @@ Changes can include workarounds or bug fixes to existing PNPM issues.
 
 ##### Version history {#javascript-pnpm-fetcherVersion-versionHistory}
 
-Version 3 is the recommended value for new packages. Versions 1 and 2 are deprecated and scheduled for removal in the 26.11 release; existing packages must migrate.
+Version 3 is the minimum supported value. Versions 1 and 2 were removed in the 26.11 release; packages that still use them fail to evaluate and must migrate to `fetcherVersion = 3` (or later) and regenerate their hashes.
 
-- 1: Initial version, nothing special.
-- 2: [Ensure consistent permissions](https://github.com/NixOS/nixpkgs/pull/422975)
+- 1: Initial version, nothing special. (removed in 26.11)
+- 2: [Ensure consistent permissions](https://github.com/NixOS/nixpkgs/pull/422975) (removed in 26.11)
 - 3: [Build a reproducible tarball](https://github.com/NixOS/nixpkgs/pull/469950)
 - 4: [Dump SQLite database to an SQL file](https://github.com/NixOS/nixpkgs/pull/522703)
 
diff --git a/doc/release-notes/rl-2611.section.md b/doc/release-notes/rl-2611.section.md
index 1df5e6b9a01c..5e674df1f8da 100644
--- a/doc/release-notes/rl-2611.section.md
+++ b/doc/release-notes/rl-2611.section.md
@@ -29,6 +29,13 @@
 
 - `librest` providing 0.7 ABI was removed. `librest_1_0` providing 1.0 ABI was renamed to `librest` and `librest_1_0` was kept as an alias.
 
+- `fetchPnpmDeps`' `fetcherVersion = 1` and `fetcherVersion = 2` have been
+  removed, as announced in the 26.05 release. Packages still using them now
+  throw an evaluation error and must migrate to `fetcherVersion = 3` (or later)
+  and regenerate their hashes. See the
+  [pnpm `fetcherVersion` section](#javascript-pnpm-fetcherVersion) of the manual
+  for details.
+
 ## Other Notable Changes {#sec-nixpkgs-release-26.11-notable-changes}
 
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->
diff --git a/pkgs/build-support/node/fetch-pnpm-deps/default.nix b/pkgs/build-support/node/fetch-pnpm-deps/default.nix
index 65d7063efac0..58e6370404ae 100644
--- a/pkgs/build-support/node/fetch-pnpm-deps/default.nix
+++ b/pkgs/build-support/node/fetch-pnpm-deps/default.nix
@@ -17,8 +17,6 @@ let
   pnpmLatest = pnpm;
 
   supportedFetcherVersions = [
-    1 # First version. Here to preserve backwards compatibility
-    2 # Ensure consistent permissions. See https://github.com/NixOS/nixpkgs/pull/422975
     3 # Build a reproducible tarball. See https://github.com/NixOS/nixpkgs/pull/469950
     4 # Dump SQLite database to an SQL file. See https://github.com/NixOS/nixpkgs/pull/522703
   ];
@@ -63,178 +61,167 @@ in
       fetcherVersion != null
       || throw "fetchPnpmDeps: `fetcherVersion` is not set, see https://nixos.org/manual/nixpkgs/stable/#javascript-pnpm-fetcherVersion.";
 
+    assert
+      !(fetcherVersion == 1 || fetcherVersion == 2)
+      || throw "fetchPnpmDeps: `fetcherVersion = ${toString fetcherVersion}` was removed in the 26.11 release. Please migrate `${pname}` to `fetcherVersion = 3` and regenerate the hash. See https://nixos.org/manual/nixpkgs/stable/#javascript-pnpm-fetcherVersion.";
+
     assert
       builtins.elem fetcherVersion supportedFetcherVersions
       || throw "fetchPnpmDeps `fetcherVersion` is not set to a supported value (${lib.concatStringsSep ", " (map toString supportedFetcherVersions)}), see https://nixos.org/manual/nixpkgs/stable/#javascript-pnpm-fetcherVersion.";
 
-    lib.warnIf (fetcherVersion < 3)
-      "fetchPnpmDeps: `fetcherVersion = ${toString fetcherVersion}` is deprecated and scheduled for removal in the 26.11 release. Please migrate `${pname}` to `fetcherVersion = 3` and regenerate the hash. See https://nixos.org/manual/nixpkgs/stable/#javascript-pnpm-fetcherVersion."
-
-      stdenvNoCC.mkDerivation
+    stdenvNoCC.mkDerivation (
+      finalAttrs:
       (
-        finalAttrs:
-        (
-          args'
-          // {
-            name = "${pname}-pnpm-deps";
+        args'
+        // {
+          name = "${pname}-pnpm-deps";
 
-            nativeBuildInputs = [
-              cacert
-              jq
-              moreutils
-              pnpm # from args
-              pnpm-fixup-state-db'
-              sqlite
-              writableTmpDirAsHomeHook
-              yq
-              zstd
-            ]
-            ++ args.nativeBuildInputs or [ ];
+          nativeBuildInputs = [
+            cacert
+            jq
+            moreutils
+            pnpm # from args
+            pnpm-fixup-state-db'
+            sqlite
+            writableTmpDirAsHomeHook
+            yq
+            zstd
+          ]
+          ++ args.nativeBuildInputs or [ ];
 
-            impureEnvVars =
-              lib.fetchers.proxyImpureEnvVars ++ [ "NIX_NPM_REGISTRY" ] ++ args.impureEnvVars or [ ];
+          impureEnvVars =
+            lib.fetchers.proxyImpureEnvVars ++ [ "NIX_NPM_REGISTRY" ] ++ args.impureEnvVars or [ ];
 
-            installPhase = ''
-              runHook preInstall
+          installPhase = ''
+            runHook preInstall
 
-              versionAtLeast () {
-                  local cur_version=$1 min_version=$2
-                  printf "%s\0%s" "$min_version" "$cur_version" | sort -zVC
-              }
+            versionAtLeast () {
+                local cur_version=$1 min_version=$2
+                printf "%s\0%s" "$min_version" "$cur_version" | sort -zVC
+            }
 
-              lockfileVersion="$(yq -r .lockfileVersion pnpm-lock.yaml)"
-              if [[ ''${lockfileVersion:0:1} -gt ${lib.versions.major pnpm.version} ]]; then
-                echo "ERROR: lockfileVersion $lockfileVersion in pnpm-lock.yaml is too new for the provided pnpm version ${lib.versions.major pnpm.version}!"
-                exit 1
+            lockfileVersion="$(yq -r .lockfileVersion pnpm-lock.yaml)"
+            if [[ ''${lockfileVersion:0:1} -gt ${lib.versions.major pnpm.version} ]]; then
+              echo "ERROR: lockfileVersion $lockfileVersion in pnpm-lock.yaml is too new for the provided pnpm version ${lib.versions.major pnpm.version}!"
+              exit 1
+            fi
+
+            # The pnpm store is bundled into a compressed tarball within $out,
+            # without distributing the uncompressed store files.
+            mkdir $out
+            storePath=$(mktemp -d)
+
+            pushd "$HOME"
+            pnpmVersion=$(pnpm --version)
+
+            if versionAtLeast "$pnpmVersion" "11"; then
+              # pnpm 11 uses a different mechanism to manage package manager versions
+              export pnpm_config_pm_on_fail=ignore
+
+              # Some packages produce platform dependent outputs. We do not want to cache those in the global store
+              export pnpm_config_side_effects_cache=false
+
+              export pnpm_config_update_notifier=false
+            else
+              pnpm config set manage-package-manager-versions false
+              pnpm config set side-effects-cache false
+              pnpm config set update-notifier false
+            fi
+            popd
+
+            pnpm config set store-dir $storePath
+
+            # Run any additional pnpm configuration commands that users provide.
+            ${prePnpmInstall}
+
+            echo "Final pnpm config:"
+            pnpm config list
+            echo
+
+            # pnpm is going to warn us about using --force
+            # --force allows us to fetch all dependencies including ones that aren't meant for our host platform
+            pnpm install \
+                --force \
+                --ignore-scripts \
+                ${lib.escapeShellArgs filterFlags} \
+                ${lib.escapeShellArgs pnpmInstallFlags} \
+                --registry="$NIX_NPM_REGISTRY" \
+                --frozen-lockfile
+
+            # Record the fetcherVersion in the output for introspection.
+            echo ${toString fetcherVersion} > $out/.fetcher-version
+
+            runHook postInstall
+          '';
+
+          fixupPhase = ''
+            runHook preFixup
+
+            # Remove timestamp and sort the json files
+            rm -rf $storePath/{v3,v10,v11}/tmp
+            for f in $(find $storePath -name "*.json"); do
+              jq --sort-keys "del(.. | .checkedAt?)" $f | sponge $f
+            done
+
+            if [ -f "$storePath/v11/index.db" ]; then
+              pnpm-fixup-state-db "$storePath/v11";
+              # Dump the SQLite database to a SQL text file for reproducibility.
+              # SQLite's binary format is non-deterministic (version-valid-for number, etc),
+              # so we store the logical contents as SQL statements and reconstruct during build.
+              if [[ ${toString fetcherVersion} -ge 4 ]]; then
+                sqlite3 "$storePath/v11/index.db" .dump > "$storePath/v11/index.db.sql"
+                rm "$storePath/v11/index.db"
               fi
+            fi
 
-              # For fetcherVersion < 3, the pnpm store files are placed directly into $out.
-              # For fetcherVersion >= 3, it is bundled into a compressed tarball within $out,
-              # without distributing the uncompressed store files.
-              if [[ ${toString fetcherVersion} -ge 3 ]]; then
-                mkdir $out
-                storePath=$(mktemp -d)
-              else
-                storePath=$out
-              fi
+            # This folder contains symlinks to /build/source which we don't need
+            # since https://github.com/pnpm/pnpm/releases/tag/v10.27.0
+            rm -rf $storePath/{v3,v10,v11}/projects
 
-              pushd "$HOME"
-              pnpmVersion=$(pnpm --version)
+            # Ensure consistent permissions
+            # NOTE: For reasons not yet fully understood, pnpm might create files with
+            # inconsistent permissions, for example inside the ubuntu-24.04
+            # github actions runner.
+            # To ensure stable derivations, we need to set permissions
+            # consistently, namely:
+            # * All files with `-exec` suffix have 555.
+            # * All other files have 444.
+            # * All folders have 555.
+            # See https://github.com/NixOS/nixpkgs/pull/350063
+            # See https://github.com/NixOS/nixpkgs/issues/422889
+            find $storePath -type f -name "*-exec" -print0 | xargs --no-run-if-empty -0 chmod 555
+            find $storePath -type f -not -name "*-exec" -print0 | xargs --no-run-if-empty -0 chmod 444
+            find $storePath -type d -print0 | xargs --no-run-if-empty -0 chmod 555
 
-              if versionAtLeast "$pnpmVersion" "11"; then
-                # pnpm 11 uses a different mechanism to manage package manager versions
-                export pnpm_config_pm_on_fail=ignore
+            (
+              cd $storePath
 
-                # Some packages produce platform dependent outputs. We do not want to cache those in the global store
-                export pnpm_config_side_effects_cache=false
+              # Build a reproducible tarball, per instructions at https://reproducible-builds.org/docs/archives/
+              tar --sort=name \
+                --mtime="@$SOURCE_DATE_EPOCH" \
+                --owner=0 --group=0 --numeric-owner \
+                --pax-option=exthdr.name=%d/PaxHeaders/%f,delete=atime,delete=ctime \
+                --zstd -cf $out/pnpm-store.tar.zst .
+            )
 
-                export pnpm_config_update_notifier=false
-              else
-                pnpm config set manage-package-manager-versions false
-                pnpm config set side-effects-cache false
-                pnpm config set update-notifier false
-              fi
-              popd
+            runHook postFixup
+          '';
 
-              pnpm config set store-dir $storePath
-
-              # Run any additional pnpm configuration commands that users provide.
-              ${prePnpmInstall}
-
-              echo "Final pnpm config:"
-              pnpm config list
-              echo
-
-              # pnpm is going to warn us about using --force
-              # --force allows us to fetch all dependencies including ones that aren't meant for our host platform
-              pnpm install \
-                  --force \
-                  --ignore-scripts \
-                  ${lib.escapeShellArgs filterFlags} \
-                  ${lib.escapeShellArgs pnpmInstallFlags} \
-                  --registry="$NIX_NPM_REGISTRY" \
-                  --frozen-lockfile
-
-              # Store newer fetcherVersion in case pnpmConfigHook also needs it
-              if [[ ${toString fetcherVersion} -gt 1 ]]; then
-                echo ${toString fetcherVersion} > $out/.fetcher-version
-              fi
-
-              runHook postInstall
-            '';
-
-            fixupPhase = ''
-              runHook preFixup
-
-              # Remove timestamp and sort the json files
-              rm -rf $storePath/{v3,v10,v11}/tmp
-              for f in $(find $storePath -name "*.json"); do
-                jq --sort-keys "del(.. | .checkedAt?)" $f | sponge $f
-              done
-
-              if [ -f "$storePath/v11/index.db" ]; then
-                pnpm-fixup-state-db "$storePath/v11";
-                # Dump the SQLite database to a SQL text file for reproducibility.
-                # SQLite's binary format is non-deterministic (version-valid-for number, etc),
-                # so we store the logical contents as SQL statements and reconstruct during build.
-                if [[ ${toString fetcherVersion} -ge 4 ]]; then
-                  sqlite3 "$storePath/v11/index.db" .dump > "$storePath/v11/index.db.sql"
-                  rm "$storePath/v11/index.db"
-                fi
-              fi
-
-              # This folder contains symlinks to /build/source which we don't need
-              # since https://github.com/pnpm/pnpm/releases/tag/v10.27.0
-              rm -rf $storePath/{v3,v10,v11}/projects
-
-              # Ensure consistent permissions
-              # NOTE: For reasons not yet fully understood, pnpm might create files with
-              # inconsistent permissions, for example inside the ubuntu-24.04
-              # github actions runner.
-              # To ensure stable derivations, we need to set permissions
-              # consistently, namely:
-              # * All files with `-exec` suffix have 555.
-              # * All other files have 444.
-              # * All folders have 555.
-              # See https://github.com/NixOS/nixpkgs/pull/350063
-              # See https://github.com/NixOS/nixpkgs/issues/422889
-              if [[ ${toString fetcherVersion} -ge 2 ]]; then
-                find $storePath -type f -name "*-exec" -print0 | xargs --no-run-if-empty -0 chmod 555
-                find $storePath -type f -not -name "*-exec" -print0 | xargs --no-run-if-empty -0 chmod 444
-                find $storePath -type d -print0 | xargs --no-run-if-empty -0 chmod 555
-              fi
-
-              if [[ ${toString fetcherVersion} -ge 3 ]]; then
-                (
-                  cd $storePath
-
-                  # Build a reproducible tarball, per instructions at https://reproducible-builds.org/docs/archives/
-                  tar --sort=name \
-                    --mtime="@$SOURCE_DATE_EPOCH" \
-                    --owner=0 --group=0 --numeric-owner \
-                    --pax-option=exthdr.name=%d/PaxHeaders/%f,delete=atime,delete=ctime \
-                    --zstd -cf $out/pnpm-store.tar.zst .
-                )
-              fi
-
-              runHook postFixup
-            '';
-
-            passthru = args.passthru or { } // {
-              inherit fetcherVersion;
-              serve = callPackage ./serve.nix {
-                inherit pnpm; # from args
-                pnpmDeps = finalAttrs.finalPackage;
-              };
+          passthru = args.passthru or { } // {
+            inherit fetcherVersion;
+            serve = callPackage ./serve.nix {
+              inherit pnpm; # from args
+              pnpmDeps = finalAttrs.finalPackage;
             };
+          };
 
-            dontConfigure = true;
-            dontBuild = true;
-            outputHashMode = "recursive";
-          }
-          // hash'
-        )
+          dontConfigure = true;
+          dontBuild = true;
+          outputHashMode = "recursive";
+        }
+        // hash'
       )
+    )
   );
 
   pnpmConfigHook = makeSetupHook {
diff --git a/pkgs/build-support/node/fetch-pnpm-deps/pnpm-config-hook.sh b/pkgs/build-support/node/fetch-pnpm-deps/pnpm-config-hook.sh
index 30c8bd444c24..5cafdd6d1d8b 100644
--- a/pkgs/build-support/node/fetch-pnpm-deps/pnpm-config-hook.sh
+++ b/pkgs/build-support/node/fetch-pnpm-deps/pnpm-config-hook.sh
@@ -40,7 +40,7 @@ pnpmConfigHook() {
 
     echo "Found 'pnpm' with version '$pnpmVersion'"
 
-    fetcherVersion=$(cat "${pnpmDeps}/.fetcher-version" || echo 1)
+    fetcherVersion=$(cat "${pnpmDeps}/.fetcher-version")
 
     echo "Using fetcherVersion: $fetcherVersion"
 
@@ -52,11 +52,7 @@ pnpmConfigHook() {
     export npm_config_platform="@npmPlatform@"
     export pnpm_config_platform="@npmPlatform@"
 
-    if [[ $fetcherVersion -ge 3 ]]; then
-      tar --zstd -xf "$pnpmDeps/pnpm-store.tar.zst" -C "$STORE_PATH"
-    else
-      cp -Tr "$pnpmDeps" "$STORE_PATH"
-    fi
+    tar --zstd -xf "$pnpmDeps/pnpm-store.tar.zst" -C "$STORE_PATH"
 
     chmod -R +w "$STORE_PATH"
 
diff --git a/pkgs/build-support/node/fetch-pnpm-deps/serve.nix b/pkgs/build-support/node/fetch-pnpm-deps/serve.nix
index 46288e974660..2c3292180d8f 100644
--- a/pkgs/build-support/node/fetch-pnpm-deps/serve.nix
+++ b/pkgs/build-support/node/fetch-pnpm-deps/serve.nix
@@ -17,8 +17,6 @@ writeShellApplication {
   text = ''
     storePath=$(mktemp -d)
 
-    fetcherVersion=$(cat "${pnpmDeps}/.fetcher-version" || echo 1)
-
     clean() {
       echo "Cleaning up temporary store at '$storePath'..."
 
@@ -27,11 +25,7 @@ writeShellApplication {
 
     echo "Copying pnpm store '${pnpmDeps}' to temporary store..."
 
-    if [[ $fetcherVersion -ge 3 ]]; then
-      tar --zstd -xf "${pnpmDeps}/pnpm-store.tar.zst" -C "$storePath"
-    else
-      cp -Tr "${pnpmDeps}" "$storePath"
-    fi
+    tar --zstd -xf "${pnpmDeps}/pnpm-store.tar.zst" -C "$storePath"
 
     chmod -R +w "$storePath"