opam: 1.2.2 -> 2.0.0 (#45806)

6 files changed, 452 insertions, 39 deletions

diff --git a/pkgs/development/tools/ocaml/opam/1.2.2.nix b/pkgs/development/tools/ocaml/opam/1.2.2.nix
new file mode 100644
index 000000000000..7e84719ae47d
--- /dev/null
+++ b/pkgs/development/tools/ocaml/opam/1.2.2.nix
@@ -0,0 +1,92 @@
+{ stdenv, lib, fetchurl, makeWrapper,
+  ocaml, unzip, ncurses, curl, aspcud
+}:
+
+assert lib.versionAtLeast ocaml.version "3.12.1";
+
+let
+  srcs = {
+    cudf = fetchurl {
+      url = "https://gforge.inria.fr/frs/download.php/file/33593/cudf-0.7.tar.gz";
+      sha256 = "92c8a9ed730bbac73f3513abab41127d966c9b9202ab2aaffcd02358c030a701";
+    };
+    extlib = fetchurl {
+      url = "http://ocaml-extlib.googlecode.com/files/extlib-1.5.3.tar.gz";
+      sha256 = "c095eef4202a8614ff1474d4c08c50c32d6ca82d1015387785cf03d5913ec021";
+    };
+    ocaml_re = fetchurl {
+      url = "https://github.com/ocaml/ocaml-re/archive/ocaml-re-1.2.0.tar.gz";
+      sha256 = "a34dd9d6136731436a963bbab5c4bbb16e5d4e21b3b851d34887a3dec451999f";
+    };
+    ocamlgraph = fetchurl {
+      url = "http://ocamlgraph.lri.fr/download/ocamlgraph-1.8.5.tar.gz";
+      sha256 = "d167466435a155c779d5ec25b2db83ad851feb42ebc37dca8ffa345ddaefb82f";
+    };
+    dose3 = fetchurl {
+      url = "https://gforge.inria.fr/frs/download.php/file/34277/dose3-3.3.tar.gz";
+      sha256 = "8dc4dae9b1a81bb3a42abb283df785ba3eb00ade29b13875821c69f03e00680e";
+    };
+    cmdliner = fetchurl {
+      url = "http://erratique.ch/software/cmdliner/releases/cmdliner-0.9.7.tbz";
+      sha256 = "9c19893cffb5d3c3469ee0cce85e3eeeba17d309b33b9ace31aba06f68f0bf7a";
+    };
+    uutf = fetchurl {
+      url = "http://erratique.ch/software/uutf/releases/uutf-0.9.3.tbz";
+      sha256 = "1f364f89b1179e5182a4d3ad8975f57389d45548735d19054845e06a27107877";
+    };
+    jsonm = fetchurl {
+      url = "http://erratique.ch/software/jsonm/releases/jsonm-0.9.1.tbz";
+      sha256 = "3fd4dca045d82332da847e65e981d8b504883571d299a3f7e71447d46bc65f73";
+    };
+    opam = fetchurl {
+      url = "https://github.com/ocaml/opam/archive/1.2.2.zip";
+      sha256 = "c590ce55ae69ec74f46215cf16a156a02b23c5f3ecb22f23a3ad9ba3d91ddb6e";
+    };
+  };
+in stdenv.mkDerivation rec {
+  name = "opam-${version}";
+  version = "1.2.2";
+
+  buildInputs = [ unzip curl ncurses ocaml makeWrapper ];
+
+  src = srcs.opam;
+
+  postUnpack = ''
+    ln -sv ${srcs.cudf} $sourceRoot/src_ext/${srcs.cudf.name}
+    ln -sv ${srcs.extlib} $sourceRoot/src_ext/${srcs.extlib.name}
+    ln -sv ${srcs.ocaml_re} $sourceRoot/src_ext/${srcs.ocaml_re.name}
+    ln -sv ${srcs.ocamlgraph} $sourceRoot/src_ext/${srcs.ocamlgraph.name}
+    ln -sv ${srcs.dose3} $sourceRoot/src_ext/${srcs.dose3.name}
+    ln -sv ${srcs.cmdliner} $sourceRoot/src_ext/${srcs.cmdliner.name}
+    ln -sv ${srcs.uutf} $sourceRoot/src_ext/${srcs.uutf.name}
+    ln -sv ${srcs.jsonm} $sourceRoot/src_ext/${srcs.jsonm.name}
+  '';
+
+  preConfigure = ''
+    substituteInPlace ./src_ext/Makefile --replace "%.stamp: %.download" "%.stamp:"
+  '';
+
+  postConfigure = "make lib-ext";
+
+  # Dirty, but apparently ocp-build requires a TERM
+  makeFlags = ["TERM=screen"];
+
+  # change argv0 to "opam" as a workaround for
+  # https://github.com/ocaml/opam/issues/2142
+  postInstall = ''
+    mv $out/bin/opam $out/bin/.opam-wrapped
+    makeWrapper $out/bin/.opam-wrapped $out/bin/opam \
+      --argv0 "opam" \
+      --suffix PATH : ${aspcud}/bin:${unzip}/bin:${curl}/bin
+  '';
+
+  doCheck = false;
+
+  meta = with stdenv.lib; {
+    description = "A package manager for OCaml";
+    homepage = http://opam.ocamlpro.com/;
+    maintainers = [ maintainers.henrytill ];
+    platforms = platforms.all;
+    license = licenses.lgpl21Plus;
+  };
+}
diff --git a/pkgs/development/tools/ocaml/opam/default.nix b/pkgs/development/tools/ocaml/opam/default.nix
index 7e84719ae47d..8e89dd3fadd2 100644
--- a/pkgs/development/tools/ocaml/opam/default.nix
+++ b/pkgs/development/tools/ocaml/opam/default.nix
@@ -1,69 +1,87 @@
-{ stdenv, lib, fetchurl, makeWrapper,
-  ocaml, unzip, ncurses, curl, aspcud
+{ stdenv, lib, fetchurl, makeWrapper, getconf,
+  ocaml, unzip, ncurses, curl, aspcud, bubblewrap
 }:
 
-assert lib.versionAtLeast ocaml.version "3.12.1";
+assert lib.versionAtLeast ocaml.version "4.02.3";
 
 let
   srcs = {
+    cmdliner = fetchurl {
+      url = "http://erratique.ch/software/cmdliner/releases/cmdliner-1.0.2.tbz";
+      sha256 = "18jqphjiifljlh9jg8zpl6310p3iwyaqphdkmf89acyaix0s4kj1";
+    };
+    cppo = fetchurl {
+      url = "https://github.com/mjambon/cppo/archive/v1.6.4.tar.gz";
+      sha256 = "0jdb7d21lfa3ck4k59mrqs5pljzq5rb504jq57nnrc6klljm42j7";
+    };
     cudf = fetchurl {
-      url = "https://gforge.inria.fr/frs/download.php/file/33593/cudf-0.7.tar.gz";
-      sha256 = "92c8a9ed730bbac73f3513abab41127d966c9b9202ab2aaffcd02358c030a701";
+      url = "https://gforge.inria.fr/frs/download.php/36602/cudf-0.9.tar.gz";
+      sha256 = "0771lwljqwwn3cryl0plny5a5dyyrj4z6bw66ha5n8yfbpcy8clr";
+    };
+    dose3 = fetchurl {
+      url = "https://gforge.inria.fr/frs/download.php/file/36063/dose3-5.0.1.tar.gz";
+      sha256 = "00yvyfm4j423zqndvgc1ycnmiffaa2l9ab40cyg23pf51qmzk2jm";
     };
     extlib = fetchurl {
-      url = "http://ocaml-extlib.googlecode.com/files/extlib-1.5.3.tar.gz";
-      sha256 = "c095eef4202a8614ff1474d4c08c50c32d6ca82d1015387785cf03d5913ec021";
+      url = "http://ygrek.org.ua/p/release/ocaml-extlib/extlib-1.7.5.tar.gz";
+      sha256 = "19slqf5bdj0rrph2w41giwmn6df2qm07942jn058pjkjrnk30d4s";
     };
-    ocaml_re = fetchurl {
-      url = "https://github.com/ocaml/ocaml-re/archive/ocaml-re-1.2.0.tar.gz";
-      sha256 = "a34dd9d6136731436a963bbab5c4bbb16e5d4e21b3b851d34887a3dec451999f";
+    jbuilder = fetchurl {
+      url = "https://github.com/ocaml/dune/releases/download/1.0+beta20/jbuilder-1.0.beta20.tbz";
+      sha256 = "07hl9as5llffgd6hbw41rs76i1ibgn3n9r0dba5h0mdlkapcwb10";
     };
-    ocamlgraph = fetchurl {
-      url = "http://ocamlgraph.lri.fr/download/ocamlgraph-1.8.5.tar.gz";
-      sha256 = "d167466435a155c779d5ec25b2db83ad851feb42ebc37dca8ffa345ddaefb82f";
+    mccs = fetchurl {
+      url = "https://github.com/AltGr/ocaml-mccs/archive/1.1+8.tar.gz";
+      sha256 = "0xavfvxfrcf3lmry8ymma1yzy0hw3ijbx94c9zq3pzlwnylrapa4";
     };
-    dose3 = fetchurl {
-      url = "https://gforge.inria.fr/frs/download.php/file/34277/dose3-3.3.tar.gz";
-      sha256 = "8dc4dae9b1a81bb3a42abb283df785ba3eb00ade29b13875821c69f03e00680e";
+    ocamlgraph = fetchurl {
+      url = "http://ocamlgraph.lri.fr/download/ocamlgraph-1.8.8.tar.gz";
+      sha256 = "0m9g16wrrr86gw4fz2fazrh8nkqms0n863w7ndcvrmyafgxvxsnr";
     };
-    cmdliner = fetchurl {
-      url = "http://erratique.ch/software/cmdliner/releases/cmdliner-0.9.7.tbz";
-      sha256 = "9c19893cffb5d3c3469ee0cce85e3eeeba17d309b33b9ace31aba06f68f0bf7a";
+    opam-file-format = fetchurl {
+      url = "https://github.com/ocaml/opam-file-format/archive/2.0.0-rc2.tar.gz";
+      sha256 = "1mgk08msp7hxn0hs0m82vky3yv6hcq4pw5402b3vhx4c49431jsb";
     };
-    uutf = fetchurl {
-      url = "http://erratique.ch/software/uutf/releases/uutf-0.9.3.tbz";
-      sha256 = "1f364f89b1179e5182a4d3ad8975f57389d45548735d19054845e06a27107877";
+    re = fetchurl {
+      url = "https://github.com/ocaml/ocaml-re/releases/download/1.7.3/re-1.7.3.tbz";
+      sha256 = "0nv933qfl8y9i19cqvhsalwzif3dkm28vg478rpnr4hgfqjlfryr";
     };
-    jsonm = fetchurl {
-      url = "http://erratique.ch/software/jsonm/releases/jsonm-0.9.1.tbz";
-      sha256 = "3fd4dca045d82332da847e65e981d8b504883571d299a3f7e71447d46bc65f73";
+    result = fetchurl {
+      url = "https://github.com/janestreet/result/releases/download/1.3/result-1.3.tbz";
+      sha256 = "1lrnbxdq80gbhnp85mqp1kfk0bkh6q1c93sfz2qgnq2qyz60w4sk";
     };
     opam = fetchurl {
-      url = "https://github.com/ocaml/opam/archive/1.2.2.zip";
-      sha256 = "c590ce55ae69ec74f46215cf16a156a02b23c5f3ecb22f23a3ad9ba3d91ddb6e";
+      url = "https://github.com/ocaml/opam/archive/2.0.0.zip";
+      sha256 = "0m4ilsldrfkkn0vlvl119bk76j2pwvqvdi8mpg957z4kqflfbfp8";
     };
   };
 in stdenv.mkDerivation rec {
   name = "opam-${version}";
-  version = "1.2.2";
+  version = "2.0.0";
 
-  buildInputs = [ unzip curl ncurses ocaml makeWrapper ];
+  buildInputs = [ unzip curl ncurses ocaml makeWrapper getconf ] ++ lib.optional stdenv.isLinux bubblewrap;
 
   src = srcs.opam;
 
   postUnpack = ''
-    ln -sv ${srcs.cudf} $sourceRoot/src_ext/${srcs.cudf.name}
-    ln -sv ${srcs.extlib} $sourceRoot/src_ext/${srcs.extlib.name}
-    ln -sv ${srcs.ocaml_re} $sourceRoot/src_ext/${srcs.ocaml_re.name}
-    ln -sv ${srcs.ocamlgraph} $sourceRoot/src_ext/${srcs.ocamlgraph.name}
-    ln -sv ${srcs.dose3} $sourceRoot/src_ext/${srcs.dose3.name}
-    ln -sv ${srcs.cmdliner} $sourceRoot/src_ext/${srcs.cmdliner.name}
-    ln -sv ${srcs.uutf} $sourceRoot/src_ext/${srcs.uutf.name}
-    ln -sv ${srcs.jsonm} $sourceRoot/src_ext/${srcs.jsonm.name}
+    ln -sv ${srcs.cmdliner} $sourceRoot/src_ext/cmdliner.tbz
+    ln -sv ${srcs.cppo} $sourceRoot/src_ext/cppo.tar.gz
+    ln -sv ${srcs.cudf} $sourceRoot/src_ext/cudf.tar.gz
+    ln -sv ${srcs.dose3} $sourceRoot/src_ext/dose3.tar.gz
+    ln -sv ${srcs.extlib} $sourceRoot/src_ext/extlib.tar.gz
+    ln -sv ${srcs.jbuilder} $sourceRoot/src_ext/jbuilder.tbz
+    ln -sv ${srcs.mccs} $sourceRoot/src_ext/mccs.tar.gz
+    ln -sv ${srcs.ocamlgraph} $sourceRoot/src_ext/ocamlgraph.tar.gz
+    ln -sv ${srcs.opam-file-format} $sourceRoot/src_ext/opam-file-format.tar.gz
+    ln -sv ${srcs.re} $sourceRoot/src_ext/re.tbz
+    ln -sv ${srcs.result} $sourceRoot/src_ext/result.tbz
   '';
 
+  patches = [ ./opam-pull-3487.patch ./opam-shebangs.patch ./opam-mccs-darwin.patch ];
+
   preConfigure = ''
     substituteInPlace ./src_ext/Makefile --replace "%.stamp: %.download" "%.stamp:"
+    patchShebangs src/state/shellscripts
   '';
 
   postConfigure = "make lib-ext";
@@ -71,13 +89,17 @@ in stdenv.mkDerivation rec {
   # Dirty, but apparently ocp-build requires a TERM
   makeFlags = ["TERM=screen"];
 
+  outputs = [ "out" "installer" ];
+  setOutputFlags = false;
+
   # change argv0 to "opam" as a workaround for
   # https://github.com/ocaml/opam/issues/2142
   postInstall = ''
     mv $out/bin/opam $out/bin/.opam-wrapped
     makeWrapper $out/bin/.opam-wrapped $out/bin/opam \
       --argv0 "opam" \
-      --suffix PATH : ${aspcud}/bin:${unzip}/bin:${curl}/bin
+      --suffix PATH : ${aspcud}/bin:${unzip}/bin:${curl}/bin:${lib.optionalString stdenv.isLinux "${bubblewrap}/bin:"}${getconf}/bin
+    $out/bin/opam-installer --prefix=$installer opam-installer.install
   '';
 
   doCheck = false;
@@ -87,6 +109,6 @@ in stdenv.mkDerivation rec {
     homepage = http://opam.ocamlpro.com/;
     maintainers = [ maintainers.henrytill ];
     platforms = platforms.all;
-    license = licenses.lgpl21Plus;
   };
 }
+# Generated by: ./opam.nix.pl -v 2.0.0 -p opam-pull-3487.patch,opam-shebangs.patch,opam-mccs-darwin.patch
diff --git a/pkgs/development/tools/ocaml/opam/opam-mccs-darwin.patch b/pkgs/development/tools/ocaml/opam/opam-mccs-darwin.patch
new file mode 100644
index 000000000000..501242c40a01
--- /dev/null
+++ b/pkgs/development/tools/ocaml/opam/opam-mccs-darwin.patch
@@ -0,0 +1,18 @@
+diff --git a/src_ext/patches/mccs/build-on-darwin.patch b/src_ext/patches/mccs/build-on-darwin.patch
+new file mode 100644
+index 00000000..157e2094
+--- /dev/null
++++ b/src_ext/patches/mccs/build-on-darwin.patch
+@@ -0,0 +1,12 @@
++diff --git a/src/context_flags.ml b/src/context_flags.ml
++index 7470030..6e07370 100644
++--- a/src/context_flags.ml
+++++ b/src/context_flags.ml
++@@ -24,6 +24,7 @@ let ifc c x = if c then x else []
++ 
++ let cxxflags =
++   let flags =
+++    (ifc (Config.system = "macosx") ["-x"; "c++"]) @
++     (ifc (Sys.win32 && Config.ccomp_type = "msvc") ["/EHsc"]) @
++     (ifc useGLPK ["-DUSEGLPK"]) @
++     (ifc useCOIN ["-DUSECOIN"]) @
diff --git a/pkgs/development/tools/ocaml/opam/opam-pull-3487.patch b/pkgs/development/tools/ocaml/opam/opam-pull-3487.patch
new file mode 100644
index 000000000000..e047c8298bc3
--- /dev/null
+++ b/pkgs/development/tools/ocaml/opam/opam-pull-3487.patch
@@ -0,0 +1,23 @@
+diff --git a/src/state/shellscripts/bwrap.sh b/src/state/shellscripts/bwrap.sh
+index 6f5d7dbea..3e1a3e1b4 100755
+--- a/src/state/shellscripts/bwrap.sh
++++ b/src/state/shellscripts/bwrap.sh
+@@ -1,4 +1,6 @@
+-#!/bin/bash -ue
++#!/usr/bin/env bash
++
++set -ue
+ 
+ if ! command -v bwrap >/dev/null; then
+     echo "The 'bwrap' command was not found. Install 'bubblewrap' on your system, or" >&2
+@@ -11,7 +13,9 @@ fi
+ 
+ ARGS=(--unshare-net --new-session)
+ ARGS=("${ARGS[@]}" --proc /proc --dev /dev)
+-ARGS=("${ARGS[@]}" --bind /tmp /tmp --tmpfs /run --tmpfs /var)
++ARGS=("${ARGS[@]}" --bind "${TMPDIR:-/tmp}" /tmp)
++ARGS=("${ARGS[@]}" --setenv TMPDIR /tmp --setenv TMP /tmp --setenv TEMPDIR /tmp --setenv TEMP /tmp)
++ARGS=("${ARGS[@]}" --tmpfs /run --tmpfs /var)
+ 
+ add_mounts() {
+     case "$1" in
diff --git a/pkgs/development/tools/ocaml/opam/opam-shebangs.patch b/pkgs/development/tools/ocaml/opam/opam-shebangs.patch
new file mode 100644
index 000000000000..f74ac84ca6b2
--- /dev/null
+++ b/pkgs/development/tools/ocaml/opam/opam-shebangs.patch
@@ -0,0 +1,128 @@
+diff --git a/src/client/opamInitDefaults.ml b/src/client/opamInitDefaults.ml
+index eca13a7c..1fd66f43 100644
+--- a/src/client/opamInitDefaults.ml
++++ b/src/client/opamInitDefaults.ml
+@@ -35,11 +35,15 @@ let eval_variables = [
+ let os_filter os =
+   FOp (FIdent ([], OpamVariable.of_string "os", None), `Eq, FString os)
+ 
++let os_distribution_filter distro =
++  FOp (FIdent ([], OpamVariable.of_string "os-distribution", None), `Eq, FString distro)
++
+ let linux_filter = os_filter "linux"
+ let macos_filter = os_filter "macos"
+ let openbsd_filter = os_filter "openbsd"
+ let freebsd_filter = os_filter "freebsd"
+ let sandbox_filter = FOr (linux_filter, macos_filter)
++let nixos_filter = os_distribution_filter "nixos"
+ 
+ let gpatch_filter = FOr (openbsd_filter, freebsd_filter)
+ let patch_filter = FNot gpatch_filter
+@@ -50,6 +54,11 @@ let wrappers ~sandboxing () =
+     CString t, None;
+   ] in
+   let w = OpamFile.Wrappers.empty in
++  let w = { w with
++            OpamFile.Wrappers.
++            pre_build = [[CString "%{hooks}%/shebangs.sh", None], Some nixos_filter];
++          }
++  in
+   if sandboxing then
+     { w with
+       OpamFile.Wrappers.
+@@ -113,6 +122,7 @@ let required_tools ~sandboxing () =
+ let init_scripts () = [
+   ("sandbox.sh", OpamScript.bwrap), Some bwrap_filter;
+   ("sandbox.sh", OpamScript.sandbox_exec), Some macos_filter;
++  ("shebangs.sh", OpamScript.patch_shebangs), Some nixos_filter;
+ ]
+ 
+ module I = OpamFile.InitConfig
+diff --git a/src/state/opamScript.mli b/src/state/opamScript.mli
+index 03449970..83de0b53 100644
+--- a/src/state/opamScript.mli
++++ b/src/state/opamScript.mli
+@@ -20,3 +20,4 @@ val env_hook : string
+ val env_hook_zsh : string
+ val env_hook_csh : string
+ val env_hook_fish : string
++val patch_shebangs : string
+diff --git a/src/state/shellscripts/patch_shebangs.sh b/src/state/shellscripts/patch_shebangs.sh
+new file mode 100755
+index 00000000..3ea84e2d
+--- /dev/null
++++ b/src/state/shellscripts/patch_shebangs.sh
+@@ -0,0 +1,73 @@
++#!/usr/bin/env bash
++# This setup hook causes the fixup phase to rewrite all script
++# interpreter file names (`#!  /path') to paths found in $PATH.  E.g.,
++# /bin/sh will be rewritten to /nix/store/<hash>-some-bash/bin/sh.
++# /usr/bin/env gets special treatment so that ".../bin/env python" is
++# rewritten to /nix/store/<hash>/bin/python.  Interpreters that are
++# already in the store are left untouched.
++
++header() { echo "$1"; }
++stopNest() { true; }
++
++fixupOutputHooks+=('if [ -z "$dontPatchShebangs" -a -e "$prefix" ]; then patchShebangs "$prefix"; fi')
++
++patchShebangs() {
++    local dir="$1"
++    header "patching script interpreter paths in $dir"
++    local f
++    local oldPath
++    local newPath
++    local arg0
++    local args
++    local oldInterpreterLine
++    local newInterpreterLine
++
++    find "$dir" -type f -perm -0100 | while read f; do
++        if [ "$(head -1 "$f" | head -c+2)" != '#!' ]; then
++            # missing shebang => not a script
++            continue
++        fi
++
++        oldInterpreterLine=$(head -1 "$f" | tail -c+3)
++        read -r oldPath arg0 args <<< "$oldInterpreterLine"
++
++        if $(echo "$oldPath" | grep -q "/bin/env$"); then
++            # Check for unsupported 'env' functionality:
++            # - options: something starting with a '-'
++            # - environment variables: foo=bar
++            if $(echo "$arg0" | grep -q -- "^-.*\|.*=.*"); then
++                echo "unsupported interpreter directive \"$oldInterpreterLine\" (set dontPatchShebangs=1 and handle shebang patching yourself)"
++                exit 1
++            fi
++            newPath="$(command -v "$arg0" || true)"
++        else
++            if [ "$oldPath" = "" ]; then
++                # If no interpreter is specified linux will use /bin/sh. Set
++                # oldpath="/bin/sh" so that we get /nix/store/.../sh.
++                oldPath="/bin/sh"
++            fi
++            newPath="$(command -v "$(basename "$oldPath")" || true)"
++            args="$arg0 $args"
++        fi
++
++        # Strip trailing whitespace introduced when no arguments are present
++        newInterpreterLine="$(echo "$newPath $args" | sed 's/[[:space:]]*$//')"
++
++        if [ -n "$oldPath" -a "${oldPath:0:${#NIX_STORE}}" != "$NIX_STORE" ]; then
++            if [ -n "$newPath" -a "$newPath" != "$oldPath" ]; then
++                echo "$f: interpreter directive changed from \"$oldInterpreterLine\" to \"$newInterpreterLine\""
++                # escape the escape chars so that sed doesn't interpret them
++                escapedInterpreterLine=$(echo "$newInterpreterLine" | sed 's|\\|\\\\|g')
++                # Preserve times, see: https://github.com/NixOS/nixpkgs/pull/33281
++                touch -r "$f" "$f.timestamp"
++                sed -i -e "1 s|.*|#\!$escapedInterpreterLine|" "$f"
++                touch -r "$f.timestamp" "$f"
++                rm "$f.timestamp"
++            fi
++        fi
++    done
++
++    stopNest
++}
++
++patchShebangs .
diff --git a/pkgs/development/tools/ocaml/opam/opam.nix.pl b/pkgs/development/tools/ocaml/opam/opam.nix.pl
new file mode 100755
index 000000000000..1862add452d6
--- /dev/null
+++ b/pkgs/development/tools/ocaml/opam/opam.nix.pl
@@ -0,0 +1,130 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings qw<all>;
+use Getopt::Std;
+
+my $gencmd = "# Generated by: " . join(" ", $0, @ARGV) . "\n";
+
+our $opt_v;
+our $opt_p;
+our $opt_r;
+our $opt_t;
+getopts "v:p:t:r:";
+
+my $OPAM_RELEASE = $opt_v // "2.0.0";
+my $OPAM_TAG = $opt_t // $OPAM_RELEASE;
+my $OPAM_GITHUB_REPO = $opt_r // "ocaml/opam";
+my $OPAM_RELEASE_URL = "https://github.com/$OPAM_GITHUB_REPO/archive/$OPAM_TAG.zip";
+my $OPAM_RELEASE_SHA256 = `nix-prefetch-url \Q$OPAM_RELEASE_URL\E`;
+chomp $OPAM_RELEASE_SHA256;
+
+my $OPAM_BASE_URL = "https://raw.githubusercontent.com/$OPAM_GITHUB_REPO/$OPAM_TAG";
+my $OPAM_OPAM = `curl -L --url \Q$OPAM_BASE_URL\E/opam-devel.opam`;
+my($OCAML_MIN_VERSION) = $OPAM_OPAM =~ /^available: ocaml-version >= "(.*)"$/m
+  or die "could not parse ocaml version bound\n";
+
+print <<"EOF";
+{ stdenv, lib, fetchurl, makeWrapper, getconf,
+  ocaml, unzip, ncurses, curl, aspcud, bubblewrap
+}:
+
+assert lib.versionAtLeast ocaml.version "$OCAML_MIN_VERSION";
+
+let
+  srcs = {
+EOF
+
+my %urls = ();
+my %md5s = ();
+
+open(SOURCES, "-|", "curl", "-L", "--url", "$OPAM_BASE_URL/src_ext/Makefile.sources");
+while (<SOURCES>) {
+  if (/^URL_(?!PKG_)([-\w]+)\s*=\s*(\S+)$/) {
+    $urls{$1} = $2;
+  } elsif (/^MD5_(?!PKG_)([-\w]+)\s*=\s*(\S+)$/) {
+    $md5s{$1} = $2;
+  }
+}
+for my $src (sort keys %urls) {
+  my ($sha256,$store_path) = split /\n/, `nix-prefetch-url --print-path \Q$urls{$src}\E`;
+  system "echo \Q$md5s{$src}\E' *'\Q$store_path\E | md5sum -c 1>&2";
+  die "md5 check failed for $urls{$src}\n" if $?;
+  print <<"EOF";
+    $src = fetchurl {
+      url = "$urls{$src}";
+      sha256 = "$sha256";
+    };
+EOF
+}
+
+print <<"EOF";
+    opam = fetchurl {
+      url = "$OPAM_RELEASE_URL";
+      sha256 = "$OPAM_RELEASE_SHA256";
+    };
+  };
+in stdenv.mkDerivation rec {
+  name = "opam-\${version}";
+  version = "$OPAM_RELEASE";
+
+  buildInputs = [ unzip curl ncurses ocaml makeWrapper getconf ] ++ lib.optional stdenv.isLinux bubblewrap;
+
+  src = srcs.opam;
+
+  postUnpack = ''
+EOF
+for my $src (sort keys %urls) {
+  my($ext) = $urls{$src} =~ /(\.(?:t(?:ar\.|)|)(?:gz|bz2?))$/
+    or die "could not find extension for $urls{$src}\n";
+  print <<"EOF";
+    ln -sv \${srcs.$src} \$sourceRoot/src_ext/$src$ext
+EOF
+}
+print <<'EOF';
+  '';
+
+EOF
+if (defined $opt_p) {
+  print "  patches = [ ";
+  for my $patch (split /[, ]/, $opt_p) {
+    $patch =~ s/^(?=[^\/]*$)/.\//;
+    print "$patch ";
+  }
+  print "];\n\n";
+}
+print <<'EOF';
+  preConfigure = ''
+    substituteInPlace ./src_ext/Makefile --replace "%.stamp: %.download" "%.stamp:"
+    patchShebangs src/state/shellscripts
+  '';
+
+  postConfigure = "make lib-ext";
+
+  # Dirty, but apparently ocp-build requires a TERM
+  makeFlags = ["TERM=screen"];
+
+  outputs = [ "out" "installer" ];
+  setOutputFlags = false;
+
+  # change argv0 to "opam" as a workaround for
+  # https://github.com/ocaml/opam/issues/2142
+  postInstall = ''
+    mv $out/bin/opam $out/bin/.opam-wrapped
+    makeWrapper $out/bin/.opam-wrapped $out/bin/opam \
+      --argv0 "opam" \
+      --suffix PATH : ${aspcud}/bin:${unzip}/bin:${curl}/bin:${lib.optionalString stdenv.isLinux "${bubblewrap}/bin:"}${getconf}/bin
+    $out/bin/opam-installer --prefix=$installer opam-installer.install
+  '';
+
+  doCheck = false;
+
+  meta = with stdenv.lib; {
+    description = "A package manager for OCaml";
+    homepage = http://opam.ocamlpro.com/;
+    maintainers = [ maintainers.henrytill ];
+    platforms = platforms.all;
+  };
+}
+EOF
+print $gencmd;