[BUG] Autoloaded -ftb-generate-complist produces 0 candidates on NixOS (home-manager)

[chowe99]

Describe the bug

On NixOS with home-manager, fzf-tab's -ftb-generate-complist autoloaded function produces 0 entries in _ftb_complist despite _ftb_compcap being correctly populated. This causes fzf-tab to silently fall back to standard zsh completion — the fzf popup never appears.

Defining the exact same function inline (not autoloaded) fixes the issue.

I can make sure:

• I am using the latest version of fzf-tab
• this is the minimal zshrc which can reproduce this bug
• fzf-tab is loaded after compinit
• fzf-tab is loaded after plugins which will wrap Tab
• fzf-tab is loaded before zsh-autosuggestions, zsh-syntax-highlighting and fast-syntax-highlighting

To Reproduce

1. Install fzf-tab via NixOS home-manager programs.zsh.plugins
2. Type ls / and press Tab
3. Standard zsh completion runs instead of fzf popup

Debug findings

Extensive debugging revealed the following chain:

Variable	Value	Expected
bindkey ^I	fzf-tab-complete	✅ Correct
IN_FZF_TAB	1 during compadd	✅ Correct
_ftb_compcap count	18 (for ls /)	✅ Correct
_ftb_complist count	0	❌ Should be 18
_ftb_finish	0	—

The compiled module path (fzf-tab-candidates-generate builtin) also produces 0 candidates. Removing the module (modules/ directory) and falling back to the pure-zsh for loop in -ftb-generate-complist also produces 0 candidates.

However, defining -ftb-generate-complist as an inline function (identical logic, not autoloaded) produces the correct 18 candidates and the fzf popup works perfectly:

# This works — defined inline in .zshrc:
-ftb-generate-complist() {
  local dsuf dpre k _v filepath first_word default_color prefix bs=$'\b'
  local -a list_colors group_colors tcandidates
  local -i same_word=1
  local -A namecolors modecolors
  (( $#_ftb_compcap == 0 )) && return
  # ... same logic as the autoloaded file ...
  typeset -gUa _ftb_complist=("${(@)tcandidates//[0-9]#$bs}")
}

Additionally, autoload +X -Uz -- -ftb-generate-complist (force-loading eagerly) works when sourced interactively but not in a fresh shell from .zshrc.

Environment

• OS: NixOS unstable (nixos-unstable, kernel 6.19.12-cachyos)
• zsh version: 5.9
• fzf version: 0.71.0
• fzf-tab version: 1.3.0 (also reproduced with 1.2.0)
• fzf-tab installed via: NixOS home-manager programs.zsh.plugins with src = "${pkgs.zsh-fzf-tab}/share/fzf-tab"
• oh-my-zsh: enabled (plugins: git, vi-mode)

Generated .zshrc loading order

1. oh-my-zsh (compinit runs here)
2. zoxide
3. fzf-tab/fzf-tab.plugin.zsh    ← plugin sourced
4. zsh-autosuggestions
5. fast-syntax-highlighting
6. zsh-syntax-highlighting
7. source <(fzf --zsh)            ← from programs.fzf
8. initContent (zstyles, aliases, bindkeys)

Minimal zshrc

autoload -Uz compinit && compinit
source /path/to/fzf-tab/fzf-tab.plugin.zsh
zstyle ':completion:*' menu no
# Type "ls /" then press Tab — no fzf popup appears

Workaround

Override -ftb-generate-complist with an inline function definition in .zshrc (after fzf-tab loads). The function body is identical to the autoloaded file — only the loading mechanism differs.