acme doesn't run under Linux/X11

[blakemcbride]

I build plan9port on my Fedora 41/X11 system. When I try acme, I get:

$ acme
usage: devdraw (don't run  directly)
acme: can't open display: muxrpc: unexpected eof

I have no idea what to do.

Thanks!

[japanoise]

Hi, I'm not an active maintainer here, but I am doing some work with the windowing code on another repo that's based on what we have here, so I might be able to help you debug/provide a bit of context.

So, libdraw is where the interface for drawing code lives, but it actually calls into a separate executable called devdraw, which communicates with your windowing system (currently either X11 or macos). I'm not positive, but it looks like for some reason, your Acme isn't calling devdraw properly - it complains if it's called without arguments - and therefore it can't connect to the display.

Have you made any patches to the repository? If not, maybe step through with a debugger or read the code and see if you can figure out why devdraw is being called without an argument?

[lufia]

Does your system have any directory in which:

plan9port/src/cmd/devdraw/mkwsysrules.sh

Lines 6 to 22 in 13582b1

	if [ -d /usr/X11R6 ]; then
	X11=/usr/X11R6
	elif [ -d /usr/local/X11R6 ]; then
	X11=/usr/local/X11R6
	elif [ -d /usr/X11R7 ]; then
	X11=/usr/X11R7
	elif [ -d /usr/X ]; then
	X11=/usr/X
	elif [ -d /usr/openwin ]; then # for Sun
	X11=/usr/openwin
	elif [ -d /usr/include/X11 ]; then
	X11=/usr
	elif [ -d /usr/local/include/X11 ]; then
	X11=/usr/local
	else
	X11=noX11dir
	fi

[blakemcbride]

$ ls /usr/include/X11/
ap_keysym.h   CoreP.h       HookObjI.h    keysymdef.h   ResourceI.h   ThreadsI.h    Xauth.h       X.h         Xosdefs.h    Xthreads.h
CallbackI.h   CreateI.h     HPkeysym.h    keysym.h      SelectionI.h  TranslateI.h  Xcms.h        XKBlib.h    Xos.h        Xtos.h
Composite.h   cursorfont.h  ICE           Object.h      Shell.h       VarargsI.h    Xcursor       XlibConf.h  Xos_r.h      Xutil.h
CompositeP.h  DECkeysym.h   ImUtil.h      ObjectP.h     ShellI.h      Vendor.h      Xdefs.h       Xlib.h      Xpoll.h      Xw32defs.h
ConstrainP.h  dri           InitialI.h    PassivGraI.h  ShellP.h      VendorP.h     XF86keysym.h  Xlibint.h   Xproto.h     XWDFile.h
Constraint.h  EventI.h      Intrinsic.h   RectObj.h     SM            Xalloca.h     Xft           Xlib-xcb.h  Xprotostr.h  Xwindows.h
ConvertI.h    extensions    IntrinsicI.h  RectObjP.h    StringDefs.h  Xarch.h       Xfuncproto.h  Xlocale.h   Xregion.h    Xwinsock.h
Core.h        fonts         IntrinsicP.h  ResConfigP.h  Sunkeysym.h   Xatom.h       Xfuncs.h      Xmd.h       Xresource.h

[blakemcbride]

I did not make any patches to the code.

[nyqvist]

Maybe the environment is not setup correctly. Have you done the following?

export PLAN9="/path/to/plan9port"
export PATH="$PATH:$PLAN9/bin"

[blakemcbride]

I checked. The environment variables are correct.

[blakemcbride]

I have an Nvidia graphics board and I use the Nvidia proprietary drivers. (If that is a factor.)

[musvaage]

Fedora 41/X11

Should one presume plot likewise doesn't run?

$ cd $PLAN9
$ grep -r "can't open display" src
src/cmd/plot/libplot/machdep.c:                 sysfatal("plot: can't open display: %r");
src/cmd/acme/acme.c:            fprint(2, "acme: can't open display: %r\n");
src/cmd/acme/acme.c:            fprint(2, "acme: can't open display: %r\n");
src/cmd/rio/main.c:             fatal("can't open display");
$ 

[blakemcbride]

I get the same thing that you do.

[aaronp24]

I gave the plan9port package on Arch Linux a try and the acme command worked fine. I also cloned the repository and built using the INSTALL command and that worked too.

For Fedora, it might be a good idea to check the system log for AVC messages and/or try running sudo setenforce 0 to disable selinux.

[blakemcbride]

I have selinux disabled. The big difference on my machine is that I am using the Nvidia proprietary drivers.

[aaronp24]

I installed Fedora 41 and I can reproduce this error, but it happens even with the out-of-the-box driver configuration. All three of these reproduced the problem:

1. Nouveau + Mesa in Wayland mode
2. NVIDIA proprietary driver in Wayland mode
3. NVIDIA proprietary driver in X11 mode

There must be some other Fedora-specific problem occurring.

[blakemcbride]

Thank you very much for all your work and the confirmation of the problem!

[sqrtiswap]

Hi, just to make sure: Did you install the required additional packages before building?
install(1) only specifies

On most Linux systems, the X11 header packages need to be installed to build using X11. On Debian. the required packages are libfontconfig1-dev, libx11-dev, libxext-dev, and libxt-dev. On Ubuntu, it suffices to install xorg-dev.

but on Fedora specifically this used to mean that

dnf install libX11-devel libXt-devel fontconfig-devel libXext-devel

was necessary to get stuff working. Could you double check this, i.e. install the requirements and rerun cd $PLAN9 && ./INSTALL?
I just tested it here on an Intel system to verify my notes and I could both reproduce the error and fix it.

[blakemcbride]

I had everything as you said but it didn't work. I think I found the problem, though. If I put $PLAN9/bin in front of the PATH rather than the back of the PATH it works. There must be something bad on my PATH.

Any chance of this working on Wayland?

Thanks!