diff --git a/.github/actions/setup/directories/action.yml b/.github/actions/setup/directories/action.yml
index bb1c92bd735..ec9c44f8b45 100644
--- a/.github/actions/setup/directories/action.yml
+++ b/.github/actions/setup/directories/action.yml
@@ -158,22 +158,9 @@ runs:
       working-directory: ${{ inputs.srcdir }}
       run: |
         ruby tool/missing-baseruby.bat --verbose
-        touch config.status .rbconfig.time
-        for mk in Makefile GNUmakefile; do
-          sed -f tool/prereq.status template/$mk.in > $mk
-        done
-        make up
+        bash tool/gen-sources.bash up
         echo RUBY_DUMP_AST=true >> "$GITHUB_ENV"
 
-    # Cleanup, runs even on failure
-    - if: always() && inputs.makeup
-      shell: bash
-      working-directory: ${{ inputs.srcdir }}
-      run: |
-        rm -f config.status .rbconfig.time \
-          Makefile GNUmakefile uncommon.mk enc.mk noarch-fake.rb
-        rm -f prism/.time prism/util/.time
-
     - if: steps.which.outputs.sudo
       shell: bash
       run: |
diff --git a/tool/gen-sources.bash b/tool/gen-sources.bash
new file mode 100644
index 00000000000..bf88c1dbfd7
--- /dev/null
+++ b/tool/gen-sources.bash
@@ -0,0 +1,51 @@
+#!/bin/bash
+set -e
+
+nop=
+dump_ast=
+
+opt= optarg=
+while getopts cd:n-: opt; do
+    optarg="$OPTARG"
+    if [[ "$opt" = - ]]; then
+        opt="-${optarg%%=*}"
+        if [[ "$optarg" = *=* ]]; then optarg="${optarg#*=}";
+        elif optarg="${!OPTIND}"; [[ "${optarg}" = -* ]]; then optarg=
+        else shift; fi
+    fi
+
+    case "-$opt" in
+        -c|--clean) nop=:;;
+        -n|--dry-run) nop=echo;;
+        -d|--dump[-_]ast) dump_ast="$optarg" RUBY_DUMP_AST=;;
+        --) break;;
+        -*) echo "${0##*/}: Unknown option $1" 1>&2; exit 1;;
+    esac
+done
+shift $((OPTIND-1))
+
+if tooldir="${0%/*}"; [ "$tooldir" = "$0" ]; then
+    tooldir=. srcdir=..
+elif srcdir="${tooldir%/*}"; [ "$srcdir" = "$tooldir" ]; then
+    srcdir=.
+fi
+template="${srcdir}/template"
+
+[ "$nop" = echo ] || trap 'rm -fr "${clean[@]}"' 0 2
+
+for t in config.status .rbconfig.time Makefile GNUmakefile; do
+    [ -z "${nop}" -a -e "$t" ] && echo "exist: $t" && exit 1
+done
+
+${nop} touch config.status .rbconfig.time
+clean=(config.status .rbconfig.time)
+for mk in Makefile GNUmakefile; do
+    [ ${nop} ] || sed -f "$tooldir/prereq.status" "$template/$mk.in" > $mk
+    clean+=("$mk")
+done
+clean+=(prism/.time prism/util/.time build-tool)
+${nop} make "HAVE_BASERUBY=yes" "BASERUBY=${RUBY-ruby}" \
+       ${RUBY_DUMP_AST:+"DUMP_AST=$RUBY_DUMP_AST" "DUMP_AST_TARGET=no"} \
+       "${@-prereq}"
+[ -z "$dump_ast" ] || ${nop} cp build-tool/dump_ast "$dump_ast"
+${nop} rm -fr "${clean[@]}"
diff --git a/tool/prereq.status b/tool/prereq.status
index a9d8f12b0aa..8edd7a3e112 100644
--- a/tool/prereq.status
+++ b/tool/prereq.status
@@ -16,6 +16,7 @@ s,@CXXFLAGS@,,g
 s,@DLDFLAGS@,,g
 s,@DTRACE_EXT@,dmyh,g
 s,@EXEEXT@,,g
+s,@GIT@,git,g
 s,@HAVE_BASERUBY@,yes,g
 s,@IFCHANGE@,tool/ifchange,g
 s,@LDFLAGS@,,g