all-packages: move fetch* to pkgs/build-support/

pkgs/build-support/fetchbitbucket/default.nix

···
+{ fetchzip }:
+
+{ owner, repo, rev, name ? "source"
+, ... # For hash agility
+}@args: fetchzip ({
+  inherit name;
+  url = "https://bitbucket.org/${owner}/${repo}/get/${rev}.tar.gz";
+  meta.homepage = "https://bitbucket.org/${owner}/${repo}/";
+  extraPostFetch = ''rm -f "$out"/.hg_archival.txt''; # impure file; see #12002
+} // removeAttrs args [ "owner" "repo" "rev" ]) // { inherit rev; }

pkgs/build-support/fetchgithub/default.nix

···
+{ lib, fetchgit, fetchzip }:
+
+{ owner, repo, rev, name ? "source"
+, fetchSubmodules ? false, private ? false
+, githubBase ? "github.com", varPrefix ? null
+, ... # For hash agility
+}@args: assert private -> !fetchSubmodules;
+let
+  baseUrl = "https://${githubBase}/${owner}/${repo}";
+  passthruAttrs = removeAttrs args [ "owner" "repo" "rev" "fetchSubmodules" "private" "githubBase" "varPrefix" ];
+  varBase = "NIX${if varPrefix == null then "" else "_${varPrefix}"}_GITHUB_PRIVATE_";
+  # We prefer fetchzip in cases we don't need submodules as the hash
+  # is more stable in that case.
+  fetcher = if fetchSubmodules then fetchgit else fetchzip;
+  privateAttrs = lib.optionalAttrs private {
+    netrcPhase = ''
+      if [ -z "''$${varBase}USERNAME" -o -z "''$${varBase}PASSWORD" ]; then
+        echo "Error: Private fetchFromGitHub requires the nix building process (nix-daemon in multi user mode) to have the ${varBase}USERNAME and ${varBase}PASSWORD env vars set." >&2
+        exit 1
+      fi
+      cat > netrc <<EOF
+      machine ${githubBase}
+              login ''$${varBase}USERNAME
+              password ''$${varBase}PASSWORD
+      EOF
+    '';
+    netrcImpureEnvVars = [ "${varBase}USERNAME" "${varBase}PASSWORD" ];
+  };
+  fetcherArgs = (if fetchSubmodules
+    then { inherit rev fetchSubmodules; url = "${baseUrl}.git"; }
+    else ({ url = "${baseUrl}/archive/${rev}.tar.gz"; } // privateAttrs)
+  ) // passthruAttrs // { inherit name; };
+in fetcher fetcherArgs // { meta.homepage = baseUrl; inherit rev; }

pkgs/build-support/fetchgitlab/default.nix

···
+{ fetchzip, lib }:
+
+# gitlab example
+{ owner, repo, rev, domain ? "gitlab.com", name ? "source", group ? null
+, ... # For hash agility
+}@args: fetchzip ({
+  inherit name;
+  url = "https://${domain}/api/v4/projects/${lib.optionalString (group != null) "${lib.replaceStrings ["."] ["%2E"] group}%2F"}${lib.replaceStrings ["."] ["%2E"] owner}%2F${lib.replaceStrings ["."] ["%2E"] repo}/repository/archive.tar.gz?sha=${rev}";
+  meta.homepage = "https://${domain}/${lib.optionalString (group != null) "${group}/"}${owner}/${repo}/";
+} // removeAttrs args [ "domain" "owner" "group" "repo" "rev" ]) // { inherit rev; }

pkgs/build-support/fetchrepoorcz/default.nix

···
+{ fetchzip }:
+
+# gitweb example, snapshot support is optional in gitweb
+{ repo, rev, name ? "source"
+, ... # For hash agility
+}@args: fetchzip ({
+  inherit name;
+  url = "https://repo.or.cz/${repo}.git/snapshot/${rev}.tar.gz";
+  meta.homepage = "https://repo.or.cz/${repo}.git/";
+} // removeAttrs args [ "repo" "rev" ]) // { inherit rev; }

pkgs/build-support/fetchsavannah/default.nix

···
+{ fetchzip }:
+
+# cgit example, snapshot support is optional in cgit
+{ repo, rev, name ? "source"
+, ... # For hash agility
+}@args: fetchzip ({
+  inherit name;
+  url = "https://git.savannah.gnu.org/cgit/${repo}.git/snapshot/${repo}-${rev}.tar.gz";
+  meta.homepage = "https://git.savannah.gnu.org/cgit/${repo}.git/";
+} // removeAttrs args [ "repo" "rev" ]) // { inherit rev; }

pkgs/top-level/all-packages.nix

···
 
   fetchCrate = callPackage ../build-support/rust/fetchcrate.nix { };
 
-  fetchFromGitHub = {
-    owner, repo, rev, name ? "source",
-    fetchSubmodules ? false, private ? false,
-    githubBase ? "github.com", varPrefix ? null,
-    ... # For hash agility
-  }@args: assert private -> !fetchSubmodules;
-  let
-    baseUrl = "https://${githubBase}/${owner}/${repo}";
-    passthruAttrs = removeAttrs args [ "owner" "repo" "rev" "fetchSubmodules" "private" "githubBase" "varPrefix" ];
-    varBase = "NIX${if varPrefix == null then "" else "_${varPrefix}"}_GITHUB_PRIVATE_";
-    # We prefer fetchzip in cases we don't need submodules as the hash
-    # is more stable in that case.
-    fetcher = if fetchSubmodules then fetchgit else fetchzip;
-    privateAttrs = lib.optionalAttrs private {
-      netrcPhase = ''
-        if [ -z "''$${varBase}USERNAME" -o -z "''$${varBase}PASSWORD" ]; then
-          echo "Error: Private fetchFromGitHub requires the nix building process (nix-daemon in multi user mode) to have the ${varBase}USERNAME and ${varBase}PASSWORD env vars set." >&2
-          exit 1
-        fi
-        cat > netrc <<EOF
-        machine ${githubBase}
-                login ''$${varBase}USERNAME
-                password ''$${varBase}PASSWORD
-        EOF
-      '';
-      netrcImpureEnvVars = [ "${varBase}USERNAME" "${varBase}PASSWORD" ];
-    };
-    fetcherArgs = (if fetchSubmodules
-        then { inherit rev fetchSubmodules; url = "${baseUrl}.git"; }
-        else ({ url = "${baseUrl}/archive/${rev}.tar.gz"; } // privateAttrs)
-      ) // passthruAttrs // { inherit name; };
-  in fetcher fetcherArgs // { meta.homepage = baseUrl; inherit rev; };
+  fetchFromGitHub = callPackage ../build-support/fetchgithub {};
 
-  fetchFromBitbucket = {
-    owner, repo, rev, name ? "source",
-    ... # For hash agility
-  }@args: fetchzip ({
-    inherit name;
-    url = "https://bitbucket.org/${owner}/${repo}/get/${rev}.tar.gz";
-    meta.homepage = "https://bitbucket.org/${owner}/${repo}/";
-    extraPostFetch = ''rm -f "$out"/.hg_archival.txt''; # impure file; see #12002
-  } // removeAttrs args [ "owner" "repo" "rev" ]) // { inherit rev; };
+  fetchFromBitbucket = callPackage ../build-support/fetchbitbucket {};
 
-  # cgit example, snapshot support is optional in cgit
-  fetchFromSavannah = {
-    repo, rev, name ? "source",
-    ... # For hash agility
-  }@args: fetchzip ({
-    inherit name;
-    url = "https://git.savannah.gnu.org/cgit/${repo}.git/snapshot/${repo}-${rev}.tar.gz";
-    meta.homepage = "https://git.savannah.gnu.org/cgit/${repo}.git/";
-  } // removeAttrs args [ "repo" "rev" ]) // { inherit rev; };
+  fetchFromSavannah = callPackage ../build-support/fetchsavannah {};
 
-  # gitlab example
-  fetchFromGitLab = {
-    owner, repo, rev, domain ? "gitlab.com", name ? "source", group ? null,
-    ... # For hash agility
-  }@args: fetchzip ({
-    inherit name;
-    url = "https://${domain}/api/v4/projects/${lib.optionalString (group != null) "${lib.replaceStrings ["."] ["%2E"] group}%2F"}${lib.replaceStrings ["."] ["%2E"] owner}%2F${lib.replaceStrings ["."] ["%2E"] repo}/repository/archive.tar.gz?sha=${rev}";
-    meta.homepage = "https://${domain}/${lib.optionalString (group != null) "${group}/"}${owner}/${repo}/";
-  } // removeAttrs args [ "domain" "owner" "group" "repo" "rev" ]) // { inherit rev; };
+  fetchFromGitLab = callPackage ../build-support/fetchgitlab {};
 
-  # gitweb example, snapshot support is optional in gitweb
-  fetchFromRepoOrCz = {
-    repo, rev, name ? "source",
-    ... # For hash agility
-  }@args: fetchzip ({
-    inherit name;
-    url = "https://repo.or.cz/${repo}.git/snapshot/${rev}.tar.gz";
-    meta.homepage = "https://repo.or.cz/${repo}.git/";
-  } // removeAttrs args [ "repo" "rev" ]) // { inherit rev; };
+  fetchFromRepoOrCz = callPackage ../build-support/fetchrepoorcz {};
 
   fetchNuGet = callPackage ../build-support/fetchnuget { };
   buildDotnetPackage = callPackage ../build-support/build-dotnet-package { };