I have a file ~/.lldbinit with a single alias:
command alias pi print (int)
But when I run my app from Xcode, the alias does not work. How
I had a similar problem. It turned out, that I had a syntax error in my .lldbinit file which leads to lldb silently ignoring the file. You can try manually loading the file with
command source ~/.lldbinit
which will show syntax errors.