clang

unvendor

06/using-nix/2a8-python.nix

@@ -0,0 +1,74 @@
+{ fetchurl, mkDerivationStage2
+, stage1, static-gnumake, static-binutils, gnugcc10 }:
+
+let
+  source-tarball-python = fetchurl {
+    # local = /downloads/Python-3.12.0.tar.xz;
+    url = "https://www.python.org/ftp/python/3.12.0/Python-3.12.0.tar.xz";
+    sha256 = "795c34f44df45a0e9b9710c8c71c15c671871524cd412ca14def212e8ccb155d";
+  };
+in
+  mkDerivationStage2 {
+    name = "bootstrap-2a8-python";
+    buildInputPaths = [
+      "${stage1.protobusybox}/bin"
+      "${static-gnumake}/wrappers"
+      "${static-binutils}/bin"
+      "${gnugcc10}/bin"
+    ];
+    script = ''
+        mkdir build-dir; cd build-dir
+        export SHELL=${stage1.protobusybox}/bin/ash
+      # alias ash to sh:
+        mkdir aliases; ln -s ${stage1.protobusybox}/bin/ash aliases/sh
+        export PATH="$(pwd)/aliases:$PATH"
+      # unpack:
+        unpack ${source-tarball-python}
+      # fixup:
+        sed -i 's|/bin/sh|${stage1.protobusybox}/bin/ash|' configure install-sh
+        sed -i 's|ac_sys_system=`uname -s`|ac_sys_system=Linux|' configure
+        # the precompiled pyc files aren't reproducible,
+        # but it's not like I need to waste time on them anyway.
+        # break their generation
+        mv Lib/compileall.py Lib/compileall.py.bak
+        echo 'import sys; sys.exit(0)' > Lib/compileall.py
+        chmod +x Lib/compileall.py
+        sed -i 's|__FILE__|"__FILE__"|' \
+          Python/errors.c \
+          Include/pyerrors.h \
+          Include/cpython/object.h \
+          Modules/pyexpat.c
+        sed -i 's|TIME __TIME__|TIME "xx:xx:xx"|' Modules/getbuildinfo.c
+        sed -i 's|DATE __DATE__|DATE "xx/xx/xx"|' Modules/getbuildinfo.c
+        # different build path length leads to different wrapping. avoid
+        sed -i 's|vars, stream=f|vars, stream=f, width=2**24|' Lib/sysconfig.py
+      # configure:
+        mkdir -p $out/lib
+        ash configure \
+          ac_cv_broken_sem_getvalue=yes \
+          ac_cv_posix_semaphores_enabled=no \
+          OPT='-DNDEBUG -fwrapv -O3 -Wall' \
+          LDFLAGS="-Wl,-rpath $out/lib" \
+          --without-static-libpython \
+          --build x86_64-linux-musl \
+          --prefix=$out \
+          --enable-shared \
+          --with-ensurepip=no
+        # ensure reproducibility in case of no /dev/shm
+        grep 'define POSIX_SEMAPHORES_NOT_ENABLED 1' pyconfig.h
+        grep 'define HAVE_BROKEN_SEM_GETVALUE 1' pyconfig.h
+      # build:
+        make -j $NPROC
+      # install:
+        make -j $NPROC install
+      # strip builddir mentions:
+        sed -i "s|$(pwd)|...|g" \
+          $out/lib/python3.*/_sysconfigdata__*.py \
+          $out/lib/python3.*/config-3.*-x86_64-linux-musl/Makefile
+        # restore compileall just in case
+        cat Lib/compileall.py.bak > $out/lib/python3.12/compileall.py
+      # check for build path leaks:
+        ( ! grep -rF $(pwd) $out )
+    '';
+  }
+