The fd 11 has an unusual mode 180

I'm trying to use Waypipe to connect to a Fedora Silverblue 33 system from a Debian Buster container on Chrome OS. I've confirmed both ends have the exact same build options, and I've tested both version 0.6.1 and 0.7.2.

Whenever I run it, I always see this result:

C4120: 65.656069 [src/shadow.c:365] The fd 11 has an unusual mode 180 (type=0): blk=0 chr=0 dir=0 lnk=0 reg=0 fifo=0 sock=0; expect an application crash!
C4120: 65.656146 [src/handlers.c:765] keymap candidate fd 11 was not file-like (type=FDC_UNKNOWN), and with size=0 did not match 48728
C4120: 65.656171 [src/shadow.c:365] The fd 11 has an unusual mode 180 (type=0): blk=0 chr=0 dir=0 lnk=0 reg=0 fifo=0 sock=0; expect an application crash!
S44675: 66.293809 [src/mainloop.c:163] Could not untranslate remote id -1 in map. Application will probably crash.
S44675: 66.293860 [src/shadow.c:332] The fd -1 is not file-like: Bad file descriptor
S44675: 66.293862 [src/handlers.c:765] keymap candidate fd -1 was not file-like (type=FDC_UNKNOWN), and with size=0 did not match 48728
S44675: 66.293869 [src/mainloop.c:122] Writing invalid fd -1
S44675: 66.293874 [src/mainloop.c:633] application write failure -1: Bad file descriptor
S44675: 66.293880 [src/mainloop.c:1509] Final write to channel was incomplete, 1+0/2
Gdk-Message: 15:42:46.293: Error 71 (Protocol error) dispatching to Wayland display.
S44675: 66.294937 [src/util.c:184] Unexpected open fd 11

This is pretty much perfectly reproducible.

I had first thought it was a wire protocol error, but again all the options and versions are the same, so I'm not sure why this would happen.

The exact options I have are:

• Both lz4 and zstd enabled.
• with_video and with_systemtap disabled.
• Weston is not found.
• The following architecture-dependent flags:

  Compiler for C supports arguments -mavx512f: YES (cached)
  Compiler for C supports arguments -mlzcnt: YES (cached)
  Compiler for C supports arguments -mbmi: YES (cached)
  Compiler for C supports arguments -mavx2: YES (cached)
  Compiler for C supports arguments -mlzcnt: YES (cached)
  Compiler for C supports arguments -mbmi: YES (cached)
  Compiler for C supports arguments -msse3: YES (cached)
  Compiler for C supports arguments -mfpu=neon: NO (cached)

I also tried a build with LZ4 and zstd disabled, to no success.