Build proot with Nix

.gitignore

@@ -0,0 +1,6 @@
+bootstrap-aarch64.zip
+bootstrap
+nix-*-aarch64-linux.tar.bz2
+proot-host
+proot-tgt
+qemu-aarch64

README.md

@@ -1,7 +1,7 @@
 # Nix-on-Droid
 
 Nix on Android, in a single-click installable package.
-It's kind of a mess for now, but hey, it works!
+It's a bit of a mess for now, but hey, it works!
 
 This script installs Nix package manager on Android.
 It does not require root, user namespaces support or disabling SELinux,
@@ -19,6 +19,7 @@ and it's probably not an easy feat to pull off.
 This repository contains the script
 that is responsible for the initial bootstrap zipball generation.
 
+
 ## Try it out
 
 Prebuilt stuff resides at https://nix-on-droid.unboiled.info

proot-tgt.REPRODUCE

@@ -1,13 +0,0 @@
-When I build it reproducibly with Nix, I get signal 7 during execution.
-At the moment the proot binary was built directly on-device in Termux.
-Sorry about that mess.
-
-Outline:
-
-* Download and compile libtalloc
-* Collect .o files into an .a static library
-* Compile proot with termux patches with:
-    * LDFLAGS += -L ../../talloc-2.1.14/
-    * LDFLAGS += -Wl,-Bstatic -ltalloc -Wl,-Bdynamic
-
-I'd be grateful if somebody could help me fix it

proot.nix

@@ -0,0 +1,132 @@
+let
+  pinnedPkgs = builtins.fetchTarball {
+    name = "nixos-unstable-2019-04-14";
+    url = https://github.com/nixos/nixpkgs/archive/acbdaa569f4ee387386ebe1b9e60b9f95b4ab21b.tar.gz;
+    sha256 = "0xzyghyxk3hwhicgdbi8yv8b8ijy1rgdsj5wb26y5j322v96zlpz";
+  };
+
+  overlay-openjdk8-linux5-fix = self: super: {
+    openjdk8 = super.openjdk8.overrideAttrs (oa: {
+      DISABLE_HOTSPOT_OS_VERSION_CHECK = "true";
+    });
+  };
+
+  overlay-jpeg-no-static = self: super: {
+    libjpeg = buildPkgs.libjpeg;
+  };
+
+  buildPkgs = import pinnedPkgs {
+    overlays = [
+      overlay-openjdk8-linux5-fix
+    ];
+  };
+
+  crossPkgs = import pinnedPkgs {
+    crossSystem = (import "${pinnedPkgs}/lib").systems.examples.aarch64-android-prebuilt;
+    overlays = [
+      overlay-openjdk8-linux5-fix
+    ];
+  };
+
+  crossStaticPkgs = import pinnedPkgs {
+    crossSystem = (import "${pinnedPkgs}/lib").systems.examples.aarch64-android-prebuilt;
+    overlays = [
+      overlay-openjdk8-linux5-fix
+    ];
+    crossOverlays = [
+      (import "${pinnedPkgs}/pkgs/top-level/static.nix")
+      overlay-jpeg-no-static
+      overlay-openjdk8-linux5-fix
+    ];
+  };
+
+
+  talloc = crossPkgs.stdenv.mkDerivation rec {
+    name = "talloc-2.1.14";
+
+    src = crossPkgs.fetchurl {
+      url = "mirror://samba/talloc/${name}.tar.gz";
+      sha256 = "1kk76dyav41ip7ddbbf04yfydb4jvywzi2ps0z2vla56aqkn11di";
+    };
+
+    depsBuildBuild = [ buildPkgs.python2 buildPkgs.zlib ];
+
+    buildDeps = [ crossPkgs.zlib ];
+
+    configurePhase = ''
+      substituteInPlace buildtools/bin/waf \
+          --replace "/usr/bin/env python" "${buildPkgs.python2}/bin/python"
+      ./configure --prefix=$out \
+          --disable-rpath \
+          --disable-python \
+          --cross-compile \
+          --cross-answers=cross-answers.txt
+    '';
+
+    buildPhase = ''
+      make
+    '';
+
+    installPhase = ''
+      mkdir -p $out/lib
+      make install
+      ${crossPkgs.stdenv.cc.targetPrefix}ar q $out/lib/libtalloc.a bin/default/talloc_[0-9]*.o
+    '';
+
+    fixupPhase = "";
+
+    prePatch = ''
+      cat <<EOF > cross-answers.txt
+      Checking uname sysname type: "Linux"
+      Checking uname machine type: "dontcare"
+      Checking uname release type: "dontcare"
+      Checking uname version type: "dontcare"
+      Checking simple C program: OK
+      building library support: OK
+      Checking for large file support: OK
+      Checking for -D_FILE_OFFSET_BITS=64: OK
+      Checking for WORDS_BIGENDIAN: OK
+      Checking for C99 vsnprintf: OK
+      Checking for HAVE_SECURE_MKSTEMP: OK
+      rpath library support: OK
+      -Wl,--version-script support: FAIL
+      Checking correct behavior of strtoll: OK
+      Checking correct behavior of strptime: OK
+      Checking for HAVE_IFACE_GETIFADDRS: OK
+      Checking for HAVE_IFACE_IFCONF: OK
+      Checking for HAVE_IFACE_IFREQ: OK
+      Checking getconf LFS_CFLAGS: OK
+      Checking for large file support without additional flags: OK
+      Checking for working strptime: OK
+      Checking for HAVE_SHARED_MMAP: OK
+      Checking for HAVE_MREMAP: OK
+      Checking for HAVE_INCOHERENT_MMAP: OK
+      Checking getconf large file support flags work: OK
+      EOF
+    '';
+  };
+
+
+  proot = crossStaticPkgs.stdenv.mkDerivation rec {
+    name = "proot-termux-${version}";
+    version = "2019-03-19";
+
+    src = crossStaticPkgs.fetchFromGitHub {
+      repo = "proot";
+      owner = "termux";
+      rev = "2a78bab91d01c723ecb7ce08069a096f6ff654c5";
+      sha256 = "1091si4i07349y7x7sx1r904gg3c9a3m39xkv24fakjlirpi3lpy";
+    };
+
+    buildInputs = [ talloc ];
+
+    makeFlags = [ "-Csrc CFLAGS=-D__ANDROID__" ];
+
+    installPhase = ''
+      mkdir -p $out/bin
+      cp src/proot $out/bin/
+    '';
+  };
+
+
+in proot

script

@@ -28,6 +28,9 @@ export PROOT_NO_SECCOMP=1  # see https://github.com/proot-me/PRoot/issues/106
 rm -rf ./bootstrap
 mkdir -p bootstrap
 
+echo "building proot-tgt (this may take a lot of time...)"
+nix build -f proot.nix -o proot-tgt
+
 wget https://github.com/proot-me/proot-static-build/blob/master/static/proot-x86_64?raw=true -O proot-host
 chmod +x proot-host
 
@@ -74,7 +77,7 @@ $PROOT_CMD "$TGT_NIX/bin/nix-store" --load-db < bootstrap/nix-installer/.reginfo
 
 echo "injecting proot..."
 mkdir -p bootstrap/bin
-cp proot-tgt bootstrap/bin/proot
+cp proot-tgt/bin/proot bootstrap/bin/proot
 
 echo "making up some resolv.conf..."
 mkdir -p bootstrap/etc