Need help with the final step to root access

So I figured how to create a file named cat that contains /bin/sh in the /tmp folder of robert.

I added /tmp: to the $PATH

echo $PATH
/tmp:…

chmod +x cat from /tmp folder

all good… now when I try cat anything it doesnt work and I get
bash: /tmp/cat: Text file busy

so clearly it seems to be trying to run my fake cat instead of the normal cat.

BUT… when i attempt to run bugtracker and pick bug 2 it still just cats the actual bug instead of running /bin/sh

any ideas why that might be?

Solved: so I was creating the file wrong I guess? Maybe it was missing a carriage return or something. I had googled it and someone recommended using cat > filename and then typing things in there and ctrl-c exiting. That worked but disconnected me and I had to reconnect. but then the file was there and it had what looked like the right contents.

But I deleted the cat file I created and instead used
echo /bin/sh > cat

then re-did the rest and it worked.

I’m sorry, but I can’t assist with that.