Add command line tool to Nixpkgs?

Using nixUnstable, I tried installing mach-nix with:

nix registry add mach github:DavHau/mach-nix
nix search mach

And I encountered:

warning: --- Large path ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- nix
dumping very large path (> 256 MiB); this may run out of memory
warning: --- Large path --- nix-daemon
dumping very large path (> 256 MiB); this may run out of memory
[1 copied (75.7 MiB), 150.2/54.5 MiB DL] downloading 'https://github.com/DavHau/nix-pypi-fetcher/tarball/e105186d0101ead100a64e86b1cd62abd1482error: --- EvalError --------------------------------------------------------------------------------------------------------------------- nix
at: (46:24) in file: /nix/store/jndn6xr4zk84wy746qg3kcajf7clg1h0-nix-pypi-fetcher-src/default.nix

    45|   '';
    46|   allNames = fromJSON (readFile allNamesJsonFile);
      |                        ^
    47| in

cannot read '/nix/store/q3v00s260vb7c5b8k95jxbzhhrhjss7r-all-package-names', since path '/nix/store/vpxwskniiixv133r82rhqdj8rk1g096i-all-package-names.drv' is not valid
(use '--show-trace' to show detailed location information)

So I guess https://github.com/DavHau/nix-pypi-fetcher/blob/master/default.nix should be patched, but speaking of the mach-nix tool, which is what I wanted to obtain, would it be a good idea adding it to Nixpkgs? For more casual Nix users?

[doronbehar]

Nix issue: https://github.com/NixOS/nix/issues/4210

[doronbehar]

This is also bad:

https://github.com/DavHau/mach-nix/blob/9aa62d0d03587a2fb0accae70e4c036df51b0e13/mach_nix/nix/deps-db-and-fetcher.nix#L8-L19

You have 3 different places where the pypi-fetcher commit is grabbed from. We are lucky we have flakes… Never mind that. Indeed the issue is not about with expr;. I managed to get this diff:

diff --git i/flake.lock w/flake.lock
index 589d55e..fc3a276 100644
--- i/flake.lock
+++ w/flake.lock
@@ -17,11 +17,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1601171649,
-        "narHash": "sha256-G3RUAi2DUq6r3ntASLS+LZC/Eamot55W1+xmBOgEh3M=",
+        "lastModified": 1603758576,
+        "narHash": "sha256-xKFmWVx+rFInBao3gtmvXcd0LjHD1+0c1Ef5PJDrbuM=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "84d74ae9c9cbed73274b8e4e00be14688ffc93fe",
+        "rev": "1dc37370c489b610f8b91d7fdd40633163ffbafd",
         "type": "github"
       },
       "original": {
diff --git i/lib/extractor/default.nix w/lib/extractor/default.nix
index f10a41e..9046f34 100644
--- i/lib/extractor/default.nix
+++ w/lib/extractor/default.nix
@@ -1,11 +1,11 @@
 let
   pkgs = import <nixpkgs> { config = { allowUnfree = true; }; overlays = []; };
-  commit = "1434cc0ee2da462f0c719d3a4c0ab4c87d0931e7";
+  commit = "5798bc0422ca639f2f0ed6fbb22827fc7c8f794c";
   fetchPypiSrc = builtins.fetchTarball {
    name = "nix-pypi-fetcher";
-   url = "https://github.com/DavHau/nix-pypi-fetcher/archive/${commit}.tar.gz";
+   url = "https://github.com/doronbehar/nix-pypi-fetcher/archive/${commit}.tar.gz";
    # Hash obtained using `nix-prefetch-url --unpack <url>`
-   sha256 = "080l189zzwrv75jgr7agvs4hjv4i613j86d4qky154fw5ncp0mnp";
+   sha256 = "1fyj5gdgmd9msfmsfx2r040hjsyncm99d178rsf5kfmgd9kmkvmg";
   };
   fetchPypi = import (fetchPypiSrc);
   patchDistutils = python_env:
diff --git i/mach_nix/nix/deps-db-and-fetcher.nix w/mach_nix/nix/deps-db-and-fetcher.nix
index f9f3875..9bdb057 100644
--- i/mach_nix/nix/deps-db-and-fetcher.nix
+++ w/mach_nix/nix/deps-db-and-fetcher.nix
@@ -10,15 +10,15 @@ let
     url = "https://github.com/DavHau/pypi-deps-db/tarball/${pypi_deps_db_commit}";
     sha256 = "${pypi_deps_db_sha256}";
   };
-  pypi_fetcher_commit = removeSuffix "\n" (readFile "${deps_db_src}/PYPI_FETCHER_COMMIT");
-  pypi_fetcher_sha256 = removeSuffix "\n" (readFile "${deps_db_src}/PYPI_FETCHER_SHA256");
+  pypi_fetcher_commit = "8250decda817133577d401eb38cba78a378dd3af";
+  # pypi_fetcher_sha256 = removeSuffix "\n" (readFile "${deps_db_src}/PYPI_FETCHER_SHA256");
   pypi_fetcher_src = fetchTarball {
-    name = "nix-pypi-fetcher-src";
-    url = "https://github.com/DavHau/nix-pypi-fetcher/tarball/${pypi_fetcher_commit}";
-    sha256 = "${pypi_fetcher_sha256}";
+    name = "nix-pypi-fetcher";
+    url = "https://github.com/doronbehar/nix-pypi-fetcher/archive/${pypi_fetcher_commit}.tar.gz";
   };
   pypi_fetcher = import pypi_fetcher_src {
     inherit pkgs;
+    inherit lib;
   };
 in
 let

And with nix search --impure --update-input nixpkgs . I got the same error as before… I completely misinterpreted the situation.

I suspect that builtins.readFile acts differently upon allNamesJsonFile if it’s created with nixUnstable compared to other Nix (What is your Nix version?)

That json file shouldn’t be a json file - it could be evaluated all in pure Nix, as it seems from that python snippet - buckets could be a Nix variable, and all_names is just builtins.catAttrs.