vimcat hangs without any output

I installed vimcat with the following method:

git clone git://github.com/rkitover/vimpager
cd vimpager
export PREFIX=~/.local
make install

┌─[jay@eagle] - [~/Work/scratchpad/vimpager] - [2021-10-05 02:37:40]
└─[0] <git:(master d9afe34✱✈) > which vimcat          
/home/jay/.local/bin/vimcat

If I try to vimcat a file, vimcat doesn't output anything and it hangs so badly I can't even kill it with ctrl+c or ctrl+d. I have to kill -9 it. It when enabling debug output, it looks like it gets stuck in a loop of waiting for a file called "vim_done":

┌─[jay@eagle] - [~/Work/scratchpad/vimpager] - [2021-10-05 02:33:49]
└─[0] <git:(master d9afe34✱✈) > vimcat -x TODO.yml 
+ tmp_dir=/tmp
+ mkdir_options=-m 700
+ uname -s
+ tmp_dir=/tmp/vimcat_32742
+ mkdir -m 700 /tmp/vimcat_32742
+ trap quit 1 PIPE HUP INT QUIT ILL TRAP KILL BUS TERM
+ tmp_file_in=/tmp/vimcat_32742/vimcat_in.txt
+ out_fifo=/tmp/vimcat_32742/vimcat_out.fifo
+ mkfifo /tmp/vimcat_32742/vimcat_out.fifo
+ [ 2 -gt 0 ]
+ shift
+ [ 1 -gt 0 ]
+ break
+ [ -d TODO.yml ]
+ [ -z  ]
+ [ ! -t 1 ]
+ [ -z  ]
+ [ -f /home/jay/.vimcatrc ]
+ vimcatrc=
+ [ 1 -eq 0 ]
+ [ -n  -a 1 -gt 1 ]
+ stty -g
+ OLDSTTY=4500:5:bf:8a3b:3:1c:7f:15:4:0:1:0:11:13:1a:0:12:f:17:16:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0
+ read_vim_settings
+ i=1
+ OLDIFS=   

+ IFS=

+ IFS=  

+ vim.basic -NEnR -i NONE +
        let g:tab_stop = 8
        if ! &et
            let g:tab_stop = &ts
        endif
        call writefile([""] + map([g:tab_stop], "\"VAL:\".v:val"), "/dev/stderr")
        quit

+ tab_stop=8
+ break
+ IFS=  

+ chunks_dir=/tmp/vimcat_32742/chunks
+ mkdir /tmp/vimcat_32742/chunks
+ i=1
+ [ 1 -ge 2 ]
+ pipeline=
+ pipeline_start=TODO.yml
+ [ 0 -eq 1 ]
+ exit_code=0
+ [ TODO.yml != - ]
+ [ ! -r TODO.yml ]
+ [ ! -s TODO.yml ]
+ [ -z  -o  = - ]
+ dest_file=/tmp/vimcat_32742/vimcat_out.fifo
+ tail_pid=32750
+ start_highlight_job
+ set -- -NEn -i NONE --cmd set runtimepath^=/home/jay/.local/vimpager/share/vimpager --cmd call vimcat#Init({ 'rc': '' }) --cmd visual -c call vimcat#Run("/tmp/vimcat_32742/vimcat_out.fifo", 0, "/tmp/vimcat_32742/chunks", "TODO.yml")
+ [ -n  ]
+ [ 0 -eq 0 ]
+ [ 8 -ne 8 ]+ 
vim_pid=32751
+ + start_pipeline:

+ + [[ ! -n -z   ] ]

+ pipeline=write_chunks
+ vim.basic -NEn -i NONE --cmd set runtimepath^=/home/jay/.local/vimpager/share/vimpager --cmd call vimcat#Init({ 'rc': '' }) --cmd visual -c+  call vimcat#Run("/tmp/vimcat_32742/vimcat_out.fifo", 0, "/tmp/vimcat_32742/chunks", "TODO.yml")cat_pid=32752

+ echo 32752
+ + + wait 32752
cat /tmp/vimcat_32742/vimcat_out.fifo
cat -- TODO.yml
+ echo 32757
+ eval write_chunks
+ write_chunks
+ cd /tmp/vimcat_32742/chunks
+ rm -f -- *
+ cat /tmp/vimcat_32742/pipeline_pid
+ split -b 4096 -
+ pipeline_pid=32757
+ [ ! -f /tmp/vimcat_32742/vim_done ]
+ do_sleep 50
+ _ms=50
+ vim.basic -NEnR -i NONE -u NONE +sleep 50 m +q
+ touch PIPELINE_DONE
+ [ ! -f /tmp/vimcat_32742/vim_done ]
+ do_sleep 50
+ _ms=50
+ vim.basic -NEnR -i NONE -u NONE +sleep 50 m +q
+ [ ! -f /tmp/vimcat_32742/vim_done ]
+ do_sleep 50
+ _ms=50
+ vim.basic -NEnR -i NONE -u NONE +sleep 50 m +q
+ [ ! -f /tmp/vimcat_32742/vim_done ]
+ do_sleep 50
+ _ms=50
+ vim.basic -NEnR -i NONE -u NONE +sleep 50 m +q
+ [ ! -f /tmp/vimcat_32742/vim_done ]
+ do_sleep 50
+ _ms=50
+ vim.basic -NEnR -i NONE -u NONE +sleep 50 m +q
+ [ ! -f /tmp/vimcat_32742/vim_done ]
+ do_sleep 50
+ _ms=50
+ vim.basic -NEnR -i NONE -u NONE +sleep 50 m +q

Some other info:

┌─[jay@eagle] - [~/Work/scratchpad/vimpager] - [2021-10-05 03:02:37]
└─[0] <git:(master d9afe34✱✈) > uname -a
Linux eagle 5.4.0-7625-generic #29~1587437458~20.04~2960161-Ubuntu SMP Tue Apr 21 05:16:44 UTC  x86_64 x86_64 x86_64 GNU/Linux
┌─[jay@eagle] - [~/Work/scratchpad/vimpager] - [2021-10-05 03:02:46]
└─[0] <git:(master d9afe34✱✈) > apt list vim
Listing... Done
vim/focal-security,focal-updates,now 2:8.1.2269-1ubuntu5.3 amd64 [installed]
vim/focal-security,focal-updates 2:8.1.2269-1ubuntu5.3 i386

rkitover / vimpager

vimcat hangs without any output #262