CMake tab completion broken

[djmitche]

When I type git add src/Ta<tab>, I get

make: invalid option -- '/'                                                                                                                                    
Usage: make [options] [target] ...                           
Options:                                                         
  ...

This only seems to happen for TaskWarrior, which is the only project I work on that uses CMake. I haven't done anything special to set up shell completion -- this is just a standard Ubuntu install of CMake. Any idea what I've done wrong?

[tbabej]

Can't reproduce with bash on Fedora. Are we on the same shell?

[djmitche]

I'm using bash..

[scottkosty]

@djmitche You might get helpful information if you run set -x before you do the tab expansion.

[djmitche]

With -x:

...
+ __git_complete_command add                            
+ local command=add                                       
+ local completion_func=_git_add                               
+ __git_have_func _git_add                       
+ declare -f -- _git_add                                                
+ __git_have_func _git_add                                              
+ declare -f -- _git_add                                                   
+ _git_add                                                          
+ case "$cur" in                                                       
+ local 'complete_opt=--others --modified --directory --no-empty-directory'
++ __git_find_on_cmdline '-u --update'                       
++ local word c=1 show_idx                                         
++ test 1 -gt 1                                                       
++ local t=1                                                          
++ cd test                                       
++ make 1/fast                                                        
make: *** No rule to make target '1/fast'.  Stop.                             
++ local 'wordlist=-u --update'                                          
++ '[' 1 -lt 2 ']'                                            
++ for word in $wordlist                                                                                                                                       
++ '[' -u = add ']'                                                                                                                                            
++ for word in $wordlist                                    
++ '[' --update = add ']'                                                    
++ (( c++ ))                                 
++ '[' 2 -lt 2 ']'                                                                                                                                             
+ test -n ''                                                 
+ local t=-n                                                              
+ cd test                                                             
+ make -n/fast                                                              
make: invalid option -- '/'                                       

The issue seems to occur only with git add (and not with, say, vi) but why would Git be running make?

[djmitche]

Also, looking at the implementation of __git_find_on_cmdline:

# Check whether one of the given words is present on the command line,
# and print the first word found.
#
# Usage: __git_find_on_cmdline [<option>]... "<wordlist>"
# --show-idx: Optionally show the index of the found word in the $words array.
__git_find_on_cmdline ()
{
    local word c="$__git_cmd_idx" show_idx

    while test $# -gt 1; do
        case "$1" in                                                                                                                                                                                                                                                                                                           
        --show-idx) show_idx=y ;;
        *)      return 1 ;; 
        esac 
        shift
    done 
    local wordlist="$1"

    while [ $c -lt $cword ]; do
        for word in $wordlist; do
            if [ "$word" = "${words[c]}" ]; then 
                if [ -n "${show_idx-}" ]; then 
                    echo "$c $word"
                else 
                    echo "$word"
                fi   
                return
            fi   
        done 
        ((c++))
    done 
}

I can see what's going on up through test 1 -g 1, and I would expect the next statement to be local 'wordlist=-u --update'. So these lines are something of a mystery:

++ local t=1                                                          
++ cd test                                       
++ make 1/fast                                                        
make: *** No rule to make target '1/fast'.  Stop.                             

I suppose those are from a concurrently executing shell? I can't find anything interestin grepping for /fast or make.*/ in my bash completions.

Even the local t= is not finding anything:

⸩ grep -r 'local t=' /usr/
/usr/lib/byobu/disk_io: local t=""
/usr/src/linux-aws-5.15-headers-5.15.0-1020/tools/testing/selftests/net/forwarding/lib.sh:              local t=$(tc_rule_stats_get $dev $((dscp + 100)))
/usr/src/linux-aws-5.15-headers-5.15.0-1020/arch/x86/boot/genimage.sh:  local t=0
/usr/src/linux-aws-headers-5.4.0-1045/tools/testing/selftests/net/forwarding/lib.sh:            local t=$(tc_rule_stats_get $dev $((dscp + 100)))
/usr/src/linux-aws-5.15-headers-5.15.0-1017/tools/testing/selftests/net/forwarding/lib.sh:              local t=$(tc_rule_stats_get $dev $((dscp + 100)))
/usr/src/linux-aws-5.15-headers-5.15.0-1017/arch/x86/boot/genimage.sh:  local t=0

and

✺ funk ~
⸩ set | grep 'local t='

[scottkosty]

@djmitche I wish I knew more but I'm not sure what's going on or where the root issue is.

[djmitche]

Well, I figured this out and the answer is kind of dumb but amusing.

I made a nice shell function to run a single test file, and I named it test.

test() {
  local t="${1}"
  ( cd test && make $t/fast && ./$t )
}

But, yeah, test is a shell builtin. So once that's in place, every use of test in a shell script -- of which there are fewer than I thought! -- will fail with some verbose error from gmake.

[scottkosty]

Thanks for coming back to this and explaining it. Good to know! I could see myself being bitten by something like this. I wonder if there are options in bash to give an error when overriding a function, which I think would have helped catch this earlier. Unfortunately, from what I understand you have to explicitly declare the function read only. Maybe there's an option to declare all functions as read only? I gave up. This was useful info though: https://unix.stackexchange.com/questions/543792/how-to-protect-bash-function-from-being-overridden-make-it-readonly