[Bug]: neovim "Man" command is broken by termux patch

[ajpaon]

Problem description

Neovim provides a plugin for viewing man pages in the editor. It's broken in termux, and I'll explain why.

The plugin works by using the man command to find the path to the man file.

When neovim was updated to 0.9 on termux, a change was made to this patch: packages/neovim/runtime-lua-man.lua that causes the plugin to use mandoc to find the file path.

ebeb10f

So now, instead of running (for example)

$ man -w man
/data/data/com.termux/files/usr/share/man/man1/man.1.gz
/data/data/com.termux/files/usr/share/man/man7/man.7.gz

We do

$ mandoc -w man
mandoc: man: BADARG: bad command line argument: No such file or directory

This error message is swallowed by the lua plugin - it really took some dedicated debugging to find the cause!

When I manually revert this change and use man instead of mandoc, the plugin works again.

It's not at all clear to me what the rationale for using mandoc here was. It's not mentioned in the commit and it's not explained in the comment change. I think it was probably an accident; AFAICT no version of mandoc supports the -w switch.

What steps will reproduce the bug?

Running this command in neovim

:Man strace

Results in the error

man.lua: "no manual entry for strace"

This is reproducible starting from nvim -u NORC, which runs neovim without my custom config.

On the other hand, running man strace in bash works fine.

What is the expected behavior?

The man page should open

System information

termux-info:

Termux Variables:
TERMUX_APK_RELEASE=F_DROID
TERMUX_APP_PACKAGE_MANAGER=apt
TERMUX_APP_PID=9706
TERMUX_IS_DEBUGGABLE_BUILD=0
TERMUX_MAIN_PACKAGE_FORMAT=debian
TERMUX_VERSION=0.118.0
Packages CPU architecture:
aarch64
Subscribed repositories:
# sources.list
deb https://packages-cf.termux.dev/apt/termux-main stable main
Updatable packages:
clang/stable 16.0.4 aarch64 [upgradable from: 16.0.3]
curl/stable 8.1.0 aarch64 [upgradable from: 8.0.1]
dos2unix/stable 7.5.0 aarch64 [upgradable from: 7.4.4]
dpkg/stable 1.21.22 aarch64 [upgradable from: 1.21.21]
fribidi/stable 1.0.13 aarch64 [upgradable from: 1.0.12]
golang/stable 3:1.20.4-1 aarch64 [upgradable from: 3:1.20.4]
libcompiler-rt/stable 16.0.4 aarch64 [upgradable from: 16.0.3]
libcurl/stable 8.1.0 aarch64 [upgradable from: 8.0.1]
libllvm/stable 16.0.4 aarch64 [upgradable from: 16.0.3]
libmpfr/stable 4.2.0-p9-0 aarch64 [upgradable from: 4.2.0-p7-0]
librav1e/stable 0.6.6 aarch64 [upgradable from: 0.6.5]
libsqlite/stable 3.42.0 aarch64 [upgradable from: 3.41.2]
libxml2/stable 2.11.4 aarch64 [upgradable from: 2.11.3]
lld/stable 16.0.4 aarch64 [upgradable from: 16.0.3]
llvm/stable 16.0.4 aarch64 [upgradable from: 16.0.3]
sqlite/stable 3.42.0 aarch64 [upgradable from: 3.41.2]
termux-tools version:
1.38.1
Android version:
13
Kernel build information:
Linux localhost 5.4.147-qgki-25884040-abT733XXU2CWC5 #1 SMP PREEMPT Thu Mar 30 20:32:41 KST 2023 aarch64 Android
Device manufacturer:
samsung
Device model:
SM-T733
LD Variables:
LD_LIBRARY_PATH=
LD_PRELOAD=/data/data/com.termux/files/usr/lib/libtermux-exec.so

[xtkoba]

The commit was "branched" from neovim-nightly package. The actual change was made in 7137f6d. Still no description though.

[ajpaon]

Thanks @xtkoba. I think it's a bug in both places :)

I just installed neovim-nightly and reproduced it there too

[ajpaon]

may I send a PR to fix this patch?

[Grimler91]

may I send a PR to fix this patch?

Please go ahead