nh fail to detect nix version when using nh clean all

[yapxuan]

I have confirmed that this is a bug related to nnh

• This is a bug, and not an user error or a support request. I understand that my issue will be closed if it is not a bug in NH.
• I have checked the issues tab and confirmed that my issue has not yet been reported. I understand that my issue will be closed if it is a duplicate.

Description

It look similar to issue #353, but cannot temporary fix with only add NH_NO_CHECKS=1. I tried nh clean user and it work fine.

Log:

~ took 4s ❯ nh clean all -v
TRACE nh::logging:86: Logging OK
DEBUG nh:27: Main {
    verbose: true,
    command: Clean(
        CleanProxy {
            command: All(
                CleanArgs {
                    keep: 1,
                    keep_since: Duration(
                        0ns,
                    ),
                    dry: false,
                    ask: false,
                    nogc: false,
                    nogcroots: false,
                },
            ),
        },
    ),
}
DEBUG nh:28: NH_VERSION=4.1.2 NH_REV=Some("8cfcd3c")
DEBUG nh::util:236: "sudo" "\'--preserve-env=NIX_PATH,NIX_CONFIG,PATH,NIX_SSL_CERT_FILE,NIX_USER_CONF_FILES,NIX_REMOTE\'" "env" "\'NH_NO_CHECKS=1\'" "\'NH_FLAKE=/home/puiyq/nixos-config-flake\'" "\'USER=puiyq\'" "\'HOME=/home/puiyq\'" "/nix/store/517civ91f0daprg37b30vhq9bz0iba5h-nh-4.1.2-8cfcd3c/bin/.nh-wrapped" "clean" "all" "-v"
TRACE nh::logging:86: Logging OK
DEBUG nh:27: Main {
    verbose: true,
    command: Clean(
        CleanProxy {
            command: All(
                CleanArgs {
                    keep: 1,
                    keep_since: Duration(
                        0ns,
                    ),
                    dry: false,
                    ask: false,
                    nogc: false,
                    nogcroots: false,
                },
            ),
        },
    ),
}
DEBUG nh:28: NH_VERSION=4.1.2 NH_REV=Some("8cfcd3c")
DEBUG nh::commands:331: cmd=Exec { nix --version }
Error:
   0: Failed to extract version

Location:
   src/util.rs:97
~ ❯ NH_NO_CHECKS=1 nh clean all -v
TRACE nh::logging:86: Logging OK
DEBUG nh:27: Main {
    verbose: true,
    command: Clean(
        CleanProxy {
            command: All(
                CleanArgs {
                    keep: 1,
                    keep_since: Duration(
                        0ns,
                    ),
                    dry: false,
                    ask: false,
                    nogc: false,
                    nogcroots: false,
                },
            ),
        },
    ),
}
DEBUG nh:28: NH_VERSION=4.1.2 NH_REV=Some("8cfcd3c")
DEBUG nh::util:236: "sudo" "\'--preserve-env=PATH,NIX_REMOTE,NIX_USER_CONF_FILES,NIX_PATH,NIX_SSL_CERT_FILE,NIX_CONFIG\'" "env" "\'NH_NO_CHECKS=1\'" "\'USER=puiyq\'" "\'HOME=/home/puiyq\'" "\'NH_FLAKE=/home/puiyq/nixos-config-flake\'" "/nix/store/517civ91f0daprg37b30vhq9bz0iba5h-nh-4.1.2-8cfcd3c/bin/.nh-wrapped" "clean" "all" "-v"
TRACE nh::logging:86: Logging OK
DEBUG nh:27: Main {
    verbose: true,
    command: Clean(
        CleanProxy {
            command: All(
                CleanArgs {
                    keep: 1,
                    keep_since: Duration(
                        0ns,
                    ),
                    dry: false,
                    ask: false,
                    nogc: false,
                    nogcroots: false,
                },
            ),
        },
    ),
}
DEBUG nh:28: NH_VERSION=4.1.2 NH_REV=Some("8cfcd3c")
DEBUG nh::commands:331: cmd=Exec { nix --version }
Error:
   0: Failed to extract version

Location:
   src/util.rs:97
~ ❯ nh clean user
! Profiles directory not found, skipping: /nix/var/nix/profiles/per-user/puiyq (nh/src/clean.rs:125)

Welcome to nh clean
Keeping 1 generation(s)
Keeping paths newer than 0s

legend:
OK: path to be kept
DEL: path to be removed

/home/puiyq/.local/state/nix/profiles/home-manager
- OK  /home/puiyq/.local/state/nix/profiles/home-manager-26-link
- DEL /home/puiyq/.local/state/nix/profiles/home-manager-25-link

> Removing /home/puiyq/.local/state/nix/profiles/home-manager-25-link
> Performing garbage collection on the nix store
492 store paths deleted, 2469.63 MiB freed``

Installation Method

NixOS (nixpkgs, pkgs.nh)

Installation Method (Other)

No response

NH Version

nh 4.1.2 (master branch)

System Information

• system: "x86_64-linux"
• host os: Linux 6.15.6, NixOS, 25.11 (Xantusia), 25.11.20250714.62e0f05
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.31pre20250712_b1245123
• nixpkgs: /nix/store/n8gf8yr0571s1ld4nr6dmk143iv3rvmh-source

[NotAShelf]

I believe this is relevant to #353 in the sense that both issues show a Nix pre-release. Something must have changed in the version command that I did not account for. I currently cannot test this due to my lack of bandwidth (as in, network bandwidth) but I'd bet the issue would go away if you entered a Nix shell with a release version of Nix and ran the command again. Either way I'll try to push a fix over the next few days.

[yapxuan]

I tried again with sudo and NH_NO_CHECKS=1, it seen work. Maybe the problem is nh clean all run with root user but the variable without sudo run with normal user,so the root user have no the local variable NH_NO_CHECKS=1.

Log:

~ took 4s ❯ sudo NH_NO_CHECKS=1 nh clean all
! Profiles directory not found, skipping: /root/.local/state/nix/profiles (nh/src/clean.rs:99)

Welcome to nh clean
Keeping 1 generation(s)
Keeping paths newer than 0s

legend:
OK: path to be kept
DEL: path to be removed

/home/puiyq/.local/state/nix/profiles/home-manager
- OK  /home/puiyq/.local/state/nix/profiles/home-manager-26-link

/nix/var/nix/profiles/system
- OK  /nix/var/nix/profiles/system-32-link

/nix/var/nix/profiles/per-user/root/channels
- OK  /nix/var/nix/profiles/per-user/root/channels-1-link

> Performing garbage collection on the nix store
12 store paths deleted, 2.09 MiB freed

[NotAShelf]

I need to check something, one moment.

[NotAShelf]

Nevermind, I'm quite positive that NH_NO_CHECKS is properly passed to all nh commands.

Submitted #359 anyway. I'll try to figure out why it required sudo in your case, the command should be automatically propagated to the escalated process.

[yapxuan]

I forgot to say I use home manager module to install it,but look like it doesn't work also when I change to system-wide install. And the new commit doesn't work for me also.
Here is log:

nixos-config-flake on  dev [!] ❯ NH_NO_CHECKS=1 nh clean all -v
TRACE nh::logging:86: Logging OK
DEBUG nh:27: Main {
    verbose: true,
    command: Clean(
        CleanProxy {
            command: All(
                CleanArgs {
                    keep: 1,
                    keep_since: Duration(
                        0ns,
                    ),
                    dry: false,
                    ask: false,
                    nogc: false,
                    nogcroots: false,
                },
            ),
        },
    ),
}
DEBUG nh:28: NH_VERSION=4.1.2 NH_REV=Some("2b96d00")
DEBUG nh::commands:157: Preserved env: HOME=/home/puiyq
DEBUG nh::commands:158: Preserved env: LOCALE_ARCHIVE=<preserved>
DEBUG nh::commands:157: Preserved env: NH_FLAKE=/home/puiyq/nixos-config-flake
DEBUG nh::commands:158: Preserved env: NIX_PATH=<preserved>
DEBUG nh::commands:158: Preserved env: PATH=<preserved>
DEBUG nh::commands:157: Preserved env: USER=puiyq
DEBUG nh::commands:157: Preserved env: NH_NO_CHECKS=1
DEBUG nh::util:236: "sudo" "\'--preserve-env=LOCALE_ARCHIVE,PATH,NIX_PATH\'" "env" "\'NH_FLAKE=/home/puiyq/nixos-config-flake\'" "\'HOME=/home/puiyq\'" "\'USER=puiyq\'" "\'NH_NO_CHECKS=1\'" "/nix/store/n1wzkc49fpvlw48dfxgrxbxmvj218y3f-nh-4.1.2-2b96d00/bin/.nh-wrapped" "clean" "all" "-v"
TRACE nh::logging:86: Logging OK
DEBUG nh:27: Main {
    verbose: true,
    command: Clean(
        CleanProxy {
            command: All(
                CleanArgs {
                    keep: 1,
                    keep_since: Duration(
                        0ns,
                    ),
                    dry: false,
                    ask: false,
                    nogc: false,
                    nogcroots: false,
                },
            ),
        },
    ),
}
DEBUG nh:28: NH_VERSION=4.1.2 NH_REV=Some("2b96d00")
DEBUG nh::commands:345: cmd=Exec { nix --version }
Error:
   0: Failed to extract version

Location:
   src/util.rs:97

[NotAShelf]

The variable is clearly preserved, that's silly. Thank you for the debug output, I'll take a closer look soon.

[NotAShelf]

Could you get me the output of nix --version in a codeblock please? I thought I had accounted for pre-release versions but I must be missing something.

[yapxuan]

~ ❯ nix --version
nix (Nix) 2.31pre20250712_b1245123

[NotAShelf]

Would you be so kind to test this patch

diff --git i/src/checks.rs w/src/checks.rs
index 875a09d..c93da3f 100644
--- i/src/checks.rs
+++ w/src/checks.rs
@@ -10,7 +10,7 @@ use crate::util::{self, NixVariant};
 
 // Static regex compiled once for version string normalization
 static VERSION_REGEX: LazyLock<Regex> =
-    LazyLock::new(|| Regex::new(r"^(\d+)\.(\d+)(?:\.(\d+))?").unwrap());
+    LazyLock::new(|| Regex::new(r"(\d+)\.(\d+)(?:\.(\d+))?(?:pre\d*)?").unwrap());
 
 /// Normalizes a version string to be compatible with semver parsing.
 ///
@@ -35,7 +35,10 @@ fn normalize_version_string(version: &str) -> String {
         let minor = captures.get(2).unwrap().as_str();
         let patch = captures.get(3).map_or("0", |m| m.as_str());
 
-        format!("{major}.{minor}.{patch}")
+        let normalized = format!("{major}.{minor}.{patch}");
+        debug!("Version normalized: '{}' -> '{}'", version, normalized);
+
+        normalized
     } else {
         // Fallback: split on common separators and take the first part
         let base_version = version
@@ -45,11 +48,14 @@ fn normalize_version_string(version: &str) -> String {
 
         // Version should have all three components (major.minor.patch)
         let parts: Vec<&str> = base_version.split('.').collect();
-        match parts.len() {
+        let normalized = match parts.len() {
             1 => format!("{}.0.0", parts[0]),            // "1" -> "1.0.0"
             2 => format!("{}.{}.0", parts[0], parts[1]), // "1.2" -> "1.2.0"
             _ => base_version.to_string(),               // "1.2.3" or more parts, use as-is
-        }
+        };
+
+        debug!("Version normalized: '{}' -> '{}'", version, normalized);
+        normalized
     }
 }

You can override nh's package and put this diff into patches with a file or with builtins.toFile.

[yapxuan]

I try patch it to the commit b1c176d but don't know why it fail to build. I am not familiar with nixos, so I search how to patch from chatgpt.

Log:

nixos-config-flake on  dev [+] ❯ nix log /nix/store/7gc1grz9b6f4pcamgr00pncvwsvk6x5m-nh-4.1.2.drv
Running phase: unpackPhase
@nix { "action": "setPhase", "phase": "unpackPhase" }
unpacking source archive /nix/store/ym2lrf7pfsyxwf6y3vzcg1nd9jcmizws-source
source root is source
Executing cargoSetupPostUnpackHook
Finished cargoSetupPostUnpackHook
Running phase: patchPhase
@nix { "action": "setPhase", "phase": "patchPhase" }
applying patch /nix/store/2vqsciw8cpwb6jdjcjn1qzxpwpfsp9kx-nh-version-normalize.patch
patching file src/checks.rs
Hunk #2 FAILED at 35.
1 out of 3 hunks FAILED -- saving rejects to file src/checks.rs.rej

overlay configuration:

nixpkgs.overlays = [
    (final: prev: {
      nh = prev.nh.overrideAttrs (old: {
        patches = (old.patches or [ ]) ++ [
          ../../nh-version-normalize.patch
        ];
      });
    })
  ];

  nixpkgs.config = {
    allowUnfree = true;
  };
  nix.package = pkgs.nixVersions.git;
  environment.systemPackages = with pkgs; [
    neovim
    nh #temporary add it to systemwide to simplify the debug operation
    wget
    curl
    just
  ];

nh-version-normalize.patch:

diff --git i/src/checks.rs w/src/checks.rs
index 875a09d..c93da3f 100644
--- a/src/checks.rs
+++ b/src/checks.rs
@@ -10,7 +10,7 @@ use crate::util::{self, NixVariant};
 
 // Static regex compiled once for version string normalization
 static VERSION_REGEX: LazyLock<Regex> =
-    LazyLock::new(|| Regex::new(r"^(\d+)\.(\d+)(?:\.(\d+))?").unwrap());
+    LazyLock::new(|| Regex::new(r"(\d+)\.(\d+)(?:\.(\d+))?(?:pre\d*)?").unwrap());
 
 /// Normalizes a version string to be compatible with semver parsing.
 ///
@@ -35,7 +35,10 @@ fn normalize_version_string(version: &str) -> String {
         let minor = captures.get(2).unwrap().as_str();
         let patch = captures.get(3).map_or("0", |m| m.as_str());
 
-        format!("{major}.{minor}.{patch}")
+        let normalized = format!("{major}.{minor}.{patch}");
+        debug!("Version normalized: '{}' -> '{}'", version, normalized);
+
+        normalized
     } else {
         // Fallback: split on common separators and take the first part
         let base_version = version
@@ -45,11 +48,14 @@ fn normalize_version_string(version: &str) -> String {
 
         // Version should have all three components (major.minor.patch)
         let parts: Vec<&str> = base_version.split('.').collect();
-        match parts.len() {
+        let normalized = match parts.len() {
             1 => format!("{}.0.0", parts[0]),            // "1" -> "1.0.0"
             2 => format!("{}.{}.0", parts[0], parts[1]), // "1.2" -> "1.2.0"
             _ => base_version.to_string(),               // "1.2.3" or more parts, use as-is
-        }
+        };
+
+        debug!("Version normalized: '{}' -> '{}'", version, normalized);
+        normalized
     }
 }

[yapxuan]

I tried fork the repo and patch it manually, sucess to build.
this is log:

nh on  master [!] is 📦 v4.1.2 via 🦀 v1.90.0-nightly took 3s ❯ NH_NO_CHECKS=1 ./result/bin/nh clean all -v
TRACE nh::logging:86: Logging OK
DEBUG nh:27: Main {
    verbose: true,
    command: Clean(
        CleanProxy {
            command: All(
                CleanArgs {
                    keep: 1,
                    keep_since: Duration(
                        0ns,
                    ),
                    dry: false,
                    ask: false,
                    nogc: false,
                    nogcroots: false,
                },
            ),
        },
    ),
}
DEBUG nh:28: NH_VERSION=4.1.2 NH_REV=Some("b1c176d-dirty")
DEBUG nh::commands:163: Preserved envs: LOCALE_ARCHIVE=<preserved>, NH_FLAKE=/home/puiyq/nixos-config-flake, NIX_PATH=<preserved>, PATH=<preserved>, USER=puiyq, NH_NO_CHECKS=1
DEBUG nh::util:236: "sudo" "\'--preserve-env=PATH,LOCALE_ARCHIVE,NIX_PATH\'" "env" "\'NH_NO_CHECKS=1\'" "\'NH_FLAKE=/home/puiyq/nixos-config-flake\'" "\'USER=puiyq\'" "/nix/store/mjrf5q2j20c3ykix93vff0ggfrbfnpkj-nh-4.1.2-b1c176d-dirty/bin/.nh-wrapped" "clean" "all" "-v"
TRACE nh::logging:86: Logging OK
DEBUG nh:27: Main {
    verbose: true,
    command: Clean(
        CleanProxy {
            command: All(
                CleanArgs {
                    keep: 1,
                    keep_since: Duration(
                        0ns,
                    ),
                    dry: false,
                    ask: false,
                    nogc: false,
                    nogcroots: false,
                },
            ),
        },
    ),
}
DEBUG nh:28: NH_VERSION=4.1.2 NH_REV=Some("b1c176d-dirty")
DEBUG nh::commands:358: cmd=Exec { nix --version }
Error:
   0: Failed to extract version

Location:
   src/util.rs:97

[NotAShelf]

I hate Nix version conventions... I'll take another look tomorrow.

[NotAShelf]

Sorry for the delay, fixed in 5157307