diff --git a/pkgs/os-specific/linux/minimal-bootstrap/gnumake/musl.nix b/pkgs/os-specific/linux/minimal-bootstrap/gnumake/musl.nix
index 1913ce85927b..7476143d3469 100644
--- a/pkgs/os-specific/linux/minimal-bootstrap/gnumake/musl.nix
+++ b/pkgs/os-specific/linux/minimal-bootstrap/gnumake/musl.nix
@@ -4,6 +4,7 @@
   hostPlatform,
   fetchurl,
   bash,
+  coreutils,
   tinycc,
   gnumakeBoot,
   gnupatch,
@@ -37,6 +38,7 @@ bash.runCommand "${pname}-${version}"
     inherit pname version meta;
 
     nativeBuildInputs = [
+      coreutils
       tinycc.compiler
       gnumakeBoot
       gnupatch
@@ -59,6 +61,13 @@ bash.runCommand "${pname}-${version}"
     tar xzf ${src}
     cd make-${version}
 
+    # Defeat parallel-build automake regen race, see gnused/default.nix.
+    touch Makefile.in Makefile aclocal.m4 config.h.in configure 2>/dev/null || true
+    for f in */Makefile.in; do touch "$f" 2>/dev/null || true; done
+    chmod +x configure config.guess config.sub install-sh missing compile \
+      depcomp mkinstalldirs help2man 2>/dev/null || true
+    [ -d build-aux ] && chmod +x build-aux/* 2>/dev/null || true
+
     # Patch
     ${lib.concatMapStringsSep "\n" (f: "patch -Np1 -i ${f}") patches}
 
diff --git a/pkgs/os-specific/linux/minimal-bootstrap/gnused/default.nix b/pkgs/os-specific/linux/minimal-bootstrap/gnused/default.nix
index 267f1f12dd20..260f9103c756 100644
--- a/pkgs/os-specific/linux/minimal-bootstrap/gnused/default.nix
+++ b/pkgs/os-specific/linux/minimal-bootstrap/gnused/default.nix
@@ -4,6 +4,7 @@
   hostPlatform,
   fetchurl,
   bash,
+  coreutils,
   gnumake,
   tinycc,
   gnused,
@@ -33,6 +34,7 @@ bash.runCommand "${pname}-${version}"
     inherit pname version meta;
 
     nativeBuildInputs = [
+      coreutils
       gnumake
       tinycc.compiler
       gnused
@@ -53,6 +55,14 @@ bash.runCommand "${pname}-${version}"
     tar xzf ${src}
     cd sed-${version}
 
+    # Defeat parallel-build automake regen race: refresh generated-file
+    # mtimes and restore +x on autotools helpers.
+    touch Makefile.in Makefile aclocal.m4 config.h.in configure 2>/dev/null || true
+    for f in */Makefile.in; do touch "$f" 2>/dev/null || true; done
+    chmod +x configure config.guess config.sub install-sh missing compile \
+      depcomp mkinstalldirs help2man 2>/dev/null || true
+    [ -d build-aux ] && chmod +x build-aux/* 2>/dev/null || true
+
     # Configure
     export CC="tcc -B ${tinycc.libs}/lib"
     export LD=tcc
diff --git a/pkgs/os-specific/linux/minimal-bootstrap/gnutar/mes.nix b/pkgs/os-specific/linux/minimal-bootstrap/gnutar/mes.nix
index 2580347d7102..f38f8e262854 100644
--- a/pkgs/os-specific/linux/minimal-bootstrap/gnutar/mes.nix
+++ b/pkgs/os-specific/linux/minimal-bootstrap/gnutar/mes.nix
@@ -4,6 +4,7 @@
   hostPlatform,
   fetchurl,
   bash,
+  coreutils,
   tinycc,
   gnumake,
   gnused,
@@ -25,6 +26,7 @@ bash.runCommand "${pname}-${version}"
     inherit pname version meta;
 
     nativeBuildInputs = [
+      coreutils
       tinycc.compiler
       gnumake
       gnused
@@ -45,6 +47,14 @@ bash.runCommand "${pname}-${version}"
     rm tar.tar
     cd tar-${version}
 
+    # untar drops mtimes and +x on autotools helpers, restore them so
+    # parallel builds don't trip into automake regeneration.
+    touch Makefile.in Makefile aclocal.m4 config.h.in configure 2>/dev/null || true
+    for f in */Makefile.in; do touch "$f" 2>/dev/null || true; done
+    chmod +x configure config.guess config.sub install-sh missing compile \
+      depcomp mkinstalldirs help2man 2>/dev/null || true
+    [ -d build-aux ] && chmod +x build-aux/* 2>/dev/null || true
+
     # Configure
     export CC="tcc -B ${tinycc.libs}/lib"
     bash ./configure \
diff --git a/pkgs/os-specific/linux/minimal-bootstrap/gnutar/musl.nix b/pkgs/os-specific/linux/minimal-bootstrap/gnutar/musl.nix
index c3e967ebe53d..09d2d260b895 100644
--- a/pkgs/os-specific/linux/minimal-bootstrap/gnutar/musl.nix
+++ b/pkgs/os-specific/linux/minimal-bootstrap/gnutar/musl.nix
@@ -4,6 +4,7 @@
   hostPlatform,
   fetchurl,
   bash,
+  coreutils,
   tinycc,
   gnumake,
   gnugrep,
@@ -26,6 +27,7 @@ bash.runCommand "${pname}-${version}"
     inherit pname version meta;
 
     nativeBuildInputs = [
+      coreutils
       tinycc.compiler
       gnumake
       gnused
@@ -46,6 +48,14 @@ bash.runCommand "${pname}-${version}"
     rm tar.tar
     cd tar-${version}
 
+    # untar drops mtimes and +x on autotools helpers, restore them so
+    # parallel builds don't trip into automake regeneration.
+    touch Makefile.in Makefile aclocal.m4 config.h.in configure 2>/dev/null || true
+    for f in */Makefile.in; do touch "$f" 2>/dev/null || true; done
+    chmod +x configure config.guess config.sub install-sh missing compile \
+      depcomp mkinstalldirs help2man 2>/dev/null || true
+    [ -d build-aux ] && chmod +x build-aux/* 2>/dev/null || true
+
     # Configure
     export CC="tcc -B ${tinycc.libs}/lib"
     export LD=tcc