"man" produces gibberish

After doing a nixos-rebuild, if I type man man, I now get:

<standard input>:4: warning: can't find character with input code 2
<standard input>:4: warning: can't find character with input code 4
<standard input>:4: warning: can't find character with input code 6
<standard input>:4: warning [p 1, 0.0i]: can't break line
<standard input>:4: warning: can't find character with input code 127
<standard input>:4: warning: can't find character with input code 7
<standard input>:5: warning: can't find character with input code 5
<standard input>:9: warning [p 1, 0.7i]: can't break line
<standard input>:10: warning: can't find character with input code 12
<standard input>:11: warning: numeric expression expected (got `J')
<standard input>:15: warning [p 1, 1.7i]: cannot adjust line
<standard input>:16: warning [p 1, 1.8i]: cannot adjust line
<standard input>:16: warning [p 1, 2.0i]: can't break line
<standard input>:19: warning: numeric expression expected (got `�')
<standard input>:19: warning [p 1, 2.5i]: cannot adjust line
<standard input>:19: warning [p 1, 2.7i]: cannot adjust line
<standard input>:19: warning [p 1, 2.8i]: cannot adjust line
<standard input>:20: cannot use character `1' as a starting delimiter
<standard input>:20: warning [p 1, 3.2i]: can't break line
^H<B5>[[w<E3><B8>~ǯ<C0>jZ<CE>h<CB>=<EE><CB>l2'<BE><B6><F8><B6>{;<B3>qv6E<B0>        Ҳ<FA><E4><C7>o]<ED><E9><C9>d2cĥP<A8><FA><EA><AB>:<B9><EB><E4><AE>'?<E8><AA>ҩTue<AA>2Sek9+<ED>R.U<CB><C9>ZVM<A6>6y]j馥)<AA><DF><D2><CB>B͵ٻʾ<CA>S<EC>/Zl5=m<B1>.<CD>|Q<C9>
... and more gibberish like that

I’m using an identical NixOS configuration (apart from hardware stuff) on another machine, and I don’t have this problem.

# nix-channel --list
nixos https://nixos.org/channels/nixos-19.03

My configuration.nix:

$ cat /etc/nixos/configuration.nix
{ config, pkgs, options, ... }:


  networking.hostName = "wombat9000"; # Define your hostname.

  imports =
    [ # Include the results of the hardware scan.


My wombat9000.nix:

$ cat /home/amy/dotWombat/nixos/wombat9000.nix
{ config, pkgs, ... }:

  boot.loader.grub.device = "/dev/sda"; # or "nodev" for efi only

My R.nix and python3.nix files are probably not relevant.

My base.nix is below. I’m guessing the problem has something to do with the i18n section, but I don’t think I’ve changed that since I first installed NixOS.

$ cat /home/amy/dotWombat/nixos/base.nix 
{ config, pkgs, options, ... }:

  # Use the GRUB 2 boot loader.
  boot.loader.grub.enable = true;
  boot.loader.grub.version = 2;
  # boot.loader.grub.efiSupport = true;
  # boot.loader.grub.efiInstallAsRemovable = true;
  # boot.loader.efi.efiSysMountPoint = "/boot/efi";
  # Define on which hard drive you want to install Grub.
  # boot.loader.grub.device = "/dev/sda"; # or "nodev" for efi only
  # boot.initrd.checkJournalingFS = false;

  # networking.wireless.enable = true;  # Enables wireless support via wpa_supplicant.

  # Configure network proxy if necessary
  # networking.proxy.default = "http://user:password@proxy:port/";
  # networking.proxy.noProxy = ",localhost,internal.domain";

  # Select internationalisation properties.
  i18n = {
    consoleFont = "Lat2-Terminus16";
    consoleKeyMap = "uk";
    defaultLocale = "en_IE.UTF-8";

  # Set your time zone.
  time.timeZone = "Europe/Dublin";

  nixpkgs.overlays = [
    (import /home/amy/nix-overlays/default.nix)

  # Allow software with an unfree license
  nixpkgs.config.allowUnfree = true;

  # Packages I want to use
  environment.systemPackages = import /home/amy/dotWombat/nixos/packages.nix pkgs;

  # Set the JAVA_HOME environment variable
  programs.java.enable = true;

  # Some programs need SUID wrappers, can be configured further or are
  # started in user sessions.
  # programs.mtr.enable = true;
  # programs.gnupg.agent = { enable = true; enableSSHSupport = true; };

  # List services that you want to enable:

  # Enable the OpenSSH daemon.
  # services.openssh.enable = true;

  # Open ports in the firewall.
  # networking.firewall.allowedTCPPorts = [ ... ];
  # networking.firewall.allowedUDPPorts = [ ... ];
  # Or disable the firewall altogether.
  # networking.firewall.enable = false;

  # Enable CUPS to print documents.
  # services.printing.enable = true;

  # Enable sound.
  sound.enable = true;
  hardware.pulseaudio.enable = true;

  # Enable the X11 windowing system.
  # services.xserver.enable = true;
  # services.xserver.layout = "uk";
  # services.xserver.xkbOptions = "eurosign:e";
  services.xserver = {
    enable = true;
    layout = "ie";
    windowManager.xmonad = {
      enable = true;
      enableContribAndExtras = true;
      extraPackages = haskellPackages: [

  # Enable touchpad support.
  # services.xserver.libinput.enable = true;

  # Enable the KDE Desktop Environment.
  services.xserver.displayManager.sddm.enable = true;
  services.xserver.desktopManager.plasma5.enable = true;

  nix.gc.automatic = true;
  nix.gc.dates = "06:15";

  # Define a user account. Don't forget to set a password with ‘passwd’.
  users.users.amy = {
    isNormalUser = true;
    home = "/home/amy";
    description = "Amy de Buitleir";
    extraGroups = [ "wheel" "networkmanager" "vboxsf" ];
    uid = 1000;

  # This value determines the NixOS release with which your system is to be
  # compatible, in order to avoid breaking some software such as database
  # servers. You should change this only after NixOS release notes say you
  # should.
  system.stateVersion = "18.09"; # Did you read the comment?

My packages.nix is probably not relevant.

$ locale

What is your new nixos-version?

$ nixos-version
19.03.173408.bd6ba87381e (Koi)

Hmm… Can’t reproduce it:

nix run -f https://github.com/NixOS/nixpkgs/archive/bd6ba87381e.tar.gz man -c env LANG=en_IE.utf8 man man

Does the above work?

Yes, that works fine.

I did a nixos-rebuild switch --upgrade, and it succeeded without errors. But now, in addition to producing the gibberish in my first post (in the pager), I get the following on stderr.

$ man man
Unrecognized line in config file (ignored)
MANDB_MAP /usr/man /var/cache/man/fsstnd
Unrecognized line in config file (ignored)
MANDB_MAP /run/current-system/sw/share/man /var/cache/man
Unrecognized line in config file (ignored)
MANDB_MAP /usr/local/man /var/cache/man/oldlocal
Unrecognized line in config file (ignored)
MANDB_MAP /run/current-system/sw/share/man /var/cache/man/local
Unrecognized line in config file (ignored)
MANDB_MAP /usr/X11R6/man /var/cache/man/X11R6
Unrecognized line in config file (ignored)
MANDB_MAP /opt/man /var/cache/man/opt
Unrecognized line in config file (ignored)
SECTION 1 n l 8 3 0 2 5 4 9 6 7

$ nixos-version
19.03.173522.021d733ea3f (Koi)

I have never made any changes to /etc/man.confsince the day I first installed NixOS. Here it is:

$ cat /etc/man.conf
# man_db.conf
# This file is used by the man-db package to configure the man and cat paths.
# It is also used to provide a manpath for those without one by examining
# their PATH environment variable. For details see the manpath(5) man page.
# Lines beginning with `#' are comments and are ignored. Any combination of
# tabs or spaces may be used as `whitespace' separators.
# There are three mappings allowed in this file:
# --------------------------------------------------------
# MANDATORY_MANPATH                     manpath_element
# MANPATH_MAP           path_element    manpath_element
# MANDB_MAP             global_manpath  [relative_catpath]
# every automatically generated MANPATH includes these fields
#MANDATORY_MANPATH                      /usr/src/pvm3/man
MANDATORY_MANPATH                       /usr/man
MANDATORY_MANPATH                       /run/current-system/sw/share/man
MANDATORY_MANPATH                       /run/current-system/sw/share/man
# set up PATH to MANPATH mapping
# ie. what man tree holds man pages for what binary directory.
#               *PATH*        ->        *MANPATH*
MANPATH_MAP     /bin                    /run/current-system/sw/share/man
MANPATH_MAP     /usr/bin                /run/current-system/sw/share/man
MANPATH_MAP     /sbin                   /run/current-system/sw/share/man
MANPATH_MAP     /usr/sbin               /run/current-system/sw/share/man
MANPATH_MAP     /usr/local/bin          /usr/local/man
MANPATH_MAP     /usr/local/bin          /run/current-system/sw/share/man
MANPATH_MAP     /usr/local/sbin         /usr/local/man
MANPATH_MAP     /usr/local/sbin         /run/current-system/sw/share/man
MANPATH_MAP     /usr/X11R6/bin          /usr/X11R6/man
MANPATH_MAP     /usr/bin/X11            /usr/X11R6/man
MANPATH_MAP     /usr/games              /run/current-system/sw/share/man
MANPATH_MAP     /opt/bin                /opt/man
MANPATH_MAP     /opt/sbin               /opt/man
# For a manpath element to be treated as a system manpath (as most of those
# above should normally be), it must be mentioned below. Each line may have
# an optional extra string indicating the catpath associated with the
# manpath. If no catpath string is used, the catpath will default to the
# given manpath.
# You *must* provide all system manpaths, including manpaths for alternate
# operating systems, locale specific manpaths, and combinations of both, if
# they exist, otherwise the permissions of the user running man/mandb will
# be used to manipulate the manual pages. Also, mandb will not initialise
# the database cache for any manpaths not mentioned below unless explicitly
# requested to do so.
# In a per-user configuration file, this directive only controls the
# location of catpaths and the creation of database caches; it has no effect
# on privileges.
# Any manpaths that are subdirectories of other manpaths must be mentioned
# *before* the containing manpath. E.g. /usr/man/preformat must be listed
# before /usr/man.
#               *MANPATH*     ->        *CATPATH*
MANDB_MAP       /usr/man                /var/cache/man/fsstnd
MANDB_MAP       /run/current-system/sw/share/man                /var/cache/man
MANDB_MAP       /usr/local/man          /var/cache/man/oldlocal
MANDB_MAP       /run/current-system/sw/share/man        /var/cache/man/local
MANDB_MAP       /usr/X11R6/man          /var/cache/man/X11R6
MANDB_MAP       /opt/man                /var/cache/man/opt
# Program definitions.  These are commented out by default as the value
# of the definition is already the default.  To change: uncomment a
# definition and modify it.
#DEFINE         pager
#DEFINE         cat     cat
#DEFINE         tr      tr '\255\267\264\327' '\055\157\047\170'
#DEFINE         grep    grep
#DEFINE         troff   groff -mandoc
#DEFINE         nroff   nroff -mandoc
#DEFINE         eqn     eqn
#DEFINE         neqn    neqn
#DEFINE         tbl     tbl
#DEFINE         col 
#DEFINE         vgrind 
#DEFINE         refer   refer
#DEFINE         grap 
#DEFINE         pic     pic -S
#DEFINE         compressor      gzip -c7
# Misc definitions: same as program definitions above.
#DEFINE         whatis_grep_flags               -i
#DEFINE         apropos_grep_flags              -iEw
#DEFINE         apropos_regex_grep_flags        -iE
# Section names. Manual sections will be searched in the order listed here;
# the default is 1, n, l, 8, 3, 0, 2, 5, 4, 9, 6, 7. Multiple SECTION
# directives may be given for clarity, and will be concatenated together in
# the expected way.
# If a particular extension is not in this list (say, 1mh), it will be
# displayed with the rest of the section it belongs to. The effect of this
# is that you only need to explicitly list extensions if you want to force a
# particular order. Sections with extensions should usually be adjacent to
# their main section (e.g. "1 1mh 8 ...").
SECTION         1 n l 8 3 0 2 5 4 9 6 7
# Range of terminal widths permitted when displaying cat pages. If the
# terminal falls outside this range, cat pages will not be created (if
# missing) or displayed.
# If CATWIDTH is set to a non-zero number, cat pages will always be
# formatted for a terminal of the given width, regardless of the width of
# the terminal actually being used. This should generally be within the
#CATWIDTH       0
# Flags.
# NOCACHE keeps man from creating cat pages.

Having the same issue on version 19.03.173682.8a3b960203b (Koi).

Any ideas?

19.03 is no longer actively maintained, I would upgrade to 19.09, follow nix - How do I upgrade Nixos to use a new channel nixos version? - Unix & Linux Stack Exchange for steps to do so

I’m on 19.09 now and I’m still having the problem on that machine. As I said before I’m using an identical NixOS configuration (apart from hardware stuff) on another machine, and I don’t have this problem there.

I’m still having this problem (on 19.09), and it’s getting kind of annoying. Does anyone have any suggestions on how I could debug the problem?

Is it possible man is an older version? For me. man --version gives:


The newer issue may be caused by man: use man-db everywhere by matthewbauer · Pull Request #65844 · NixOS/nixpkgs · GitHub.

Yes, 19.09 is using an older version. So maybe when the next release comes out, this problem will go away.

$ man --version
man, version 1.6g

That looks like an even older man version. Perhaps sudo nix-env -e man and nix-env -e man fixes it?

1 Like

Thank you; you led me to the solution!

On another one of my machines, man works fine, and man --version gives man IAll of my machines are single-user, and I use the exact same NixOS configuration and dotfiles on all of them.

Normally, I never install anything as a user, but I ran nix-env -q, and man was in the list! Why did I install it locally? Years ago I was following instructions in one of the Nix pills : NixOS - Nix Pills! I’ll suggest to the author that he or she instruct the user to uninstall the local copy after playing around with it, to make sure that they don’t get weird behaviour like I did.

TL;DR, nix-env -e man fixed it.

1 Like