From f2e2502412a661bc371c7390d86de278c4b9ef97 Mon Sep 17 00:00:00 2001
From: Nicolas Mattia <nicolas@nmattia.com>
Date: Sat, 22 Feb 2020 18:41:39 +0100
Subject: [PATCH] Don't IFD when testing README

---
 README.md   |  7 -------
 default.nix | 42 ++++++++++++++++++++++++------------------
 2 files changed, 24 insertions(+), 25 deletions(-)

diff --git a/README.md b/README.md
index f3db944..407631a 100644
--- a/README.md
+++ b/README.md
@@ -223,7 +223,6 @@ Available commands:
   modify                   Modify dependency attributes without performing an
                            update
   drop                     Drop dependency
-
 ```
 
 #### Add
@@ -261,7 +260,6 @@ Available options:
 Experimental commands:
   git                      Add a git dependency. Experimental.
   github                   Add a GitHub dependency
-
 ```
 
 #### Update
@@ -294,7 +292,6 @@ Available options:
                            'file' or 'tarball'. If not set, the value is
                            inferred from the suffix of the URL.
   -h,--help                Show this help text
-
 ```
 
 #### Modify
@@ -327,7 +324,6 @@ Available options:
                            'file' or 'tarball'. If not set, the value is
                            inferred from the suffix of the URL.
   -h,--help                Show this help text
-
 ```
 
 #### Drop
@@ -343,7 +339,6 @@ Usage: niv drop PACKAGE [ATTRIBUTE]
 
 Available options:
   -h,--help                Show this help text
-
 ```
 
 #### Init
@@ -354,7 +349,6 @@ Usage: niv init
 
 Available options:
   -h,--help                Show this help text
-
 ```
 
 #### show
@@ -364,7 +358,6 @@ Usage: niv show [PACKAGE]
 
 Available options:
   -h,--help                Show this help text
-
 ```
 
 [Nix]: https://nixos.org/nix/
diff --git a/default.nix b/default.nix
index 53d5bff..7633431 100644
--- a/default.nix
+++ b/default.nix
@@ -195,24 +195,30 @@ rec
   tests-github = pkgs.callPackage ./tests/github { inherit niv; };
   tests-git = pkgs.callPackage ./tests/git { inherit niv; };
 
-  readme = pkgs.writeText "README.md" (
-    let
-      template = builtins.readFile ./README.tpl.md;
-      niv_help = builtins.readFile (
-        pkgs.runCommand "niv_help" { buildInputs = [ niv ]; }
-          "niv --help > $out"
-      );
-      niv_cmd_help = cmd: builtins.readFile (
-        pkgs.runCommand "niv_${cmd}_help" { buildInputs = [ niv ]; }
-          "niv ${cmd} --help > $out"
-      );
-      cmds = [ "add" "update" "modify" "drop" "init" "show" ];
-    in
-      pkgs.lib.replaceStrings
-        ([ "replace_niv_help" ] ++ (map (cmd: "replace_niv_${cmd}_help") cmds))
-        ([ niv_help ] ++ (map niv_cmd_help cmds))
-        template
-  );
+  readme = pkgs.runCommand "README.md" { nativeBuildInputs = [ niv ]; }
+    ''
+      cp ${./README.tpl.md} $out
+      sed -i "/replace_niv_help/r"<(niv --help) $out
+      sed -i "/replace_niv_help/d" $out
+
+      sed -i "/replace_niv_add_help/r"<(niv add --help) $out
+      sed -i "/replace_niv_add_help/d" $out
+
+      sed -i "/replace_niv_update_help/r"<(niv update --help) $out
+      sed -i "/replace_niv_update_help/d" $out
+
+      sed -i "/replace_niv_modify_help/r"<(niv modify --help) $out
+      sed -i "/replace_niv_modify_help/d" $out
+
+      sed -i "/replace_niv_drop_help/r"<(niv drop --help) $out
+      sed -i "/replace_niv_drop_help/d" $out
+
+      sed -i "/replace_niv_init_help/r"<(niv init --help) $out
+      sed -i "/replace_niv_init_help/d" $out
+
+      sed -i "/replace_niv_show_help/r"<(niv show --help) $out
+      sed -i "/replace_niv_show_help/d" $out
+    '';
 
   readme-test = pkgs.runCommand "README-test" {}
     ''