OSX 10.11.6 lldb says Breakpoint 1: no locations (pending) - c

Question

I have what should be an elementary activity with C, Make and lldb on OSX, that seems to not be working as-specified in the documentation. The simple C-coding exercise to learn the "lldb" Debugger, is Exercise-4 from "Learning C The Hard Way" (Shaw, Zed A., 2015), so it's a well-worn, no complexities example of how this should work. Only OSX doesn't behave the way its Man and Help pages say it should.
Is there something fundamentally missing from the Makefile? Is the documentation giving me incorrect syntax? Is there a bug with this version of OSX or the compiler, or lldb? Can you just not set Breakpoints on the main() method in C on OSX, so the exercise is fundamentally flawed and no-one noticed for two years?
Thanks for taking the time to look it over ...
Here's the whole use-case output:
My-MacBook-Pro:Exercises Me$ ls -als total 48
0 drwxr-xr-x 7 Me staff 238 Mar 12 20:56 .
0 drwxr-xr-x 8 Me staff 272 Feb 26 02:11 ..
24 -rw-r--r--# 1 Me staff 10244 Mar 12 20:56 .DS_Store
0 drwxr-xr-x 5 Me staff 170 Mar 3 02:48 BonusContent
8 -rw-r--r--# 1 Me staff 48 Mar 12 20:56 Makefile
8 -rw-r--r--# 1 Me staff 322 Feb 28 00:50 ex1.c
8 -rw-r--r-- 1 v staff 184 Mar 12 19:53 ex3.c
My-MacBook-Pro:Exercises Me$ cat ex3.c
#include <stdio.h>
int main(int argc, char *argv[])
{
int age = 10;
int height = 72;
printf(" I am %d years old.\n", age);
printf(" I am %d inches tall.\n", height);
return 0;
}
My-MacBook-Pro:Exercises Me$ cat Makefile
CFLAGS=-Wall -g
all: ex3
clean:
rm -f ex3
My-MacBook-Pro:Exercises Me$ make ex3
cc -Wall -g ex3.c -o ex3
My-MacBook-Pro:Exercises Me$
My-MacBook-Pro:Exercises Me$ lldb ex3
(lldb) target create "ex3"
Current executable set to 'ex3' (x86_64).
(lldb) breakpoint set --method main
Breakpoint 1: no locations (pending).
WARNING: Unable to resolve breakpoint to any actual locations.
(lldb)
My-MacBook-Pro:Exercises Me$ ls -als
total 72
0 drwxr-xr-x 9 Me staff 306 Mar 12 20:57 .
0 drwxr-xr-x 8 Me staff 272 Feb 26 02:11 ..
24 -rw-r--r--# 1 Me staff 10244 Mar 12 20:57 .DS_Store
0 drwxr-xr-x 5 Me staff 170 Mar 3 02:48 BonusContent
8 -rw-r--r--# 1 Me staff 48 Mar 12 20:56 Makefile
8 -rw-r--r--# 1 Me staff 322 Feb 28 00:50 ex1.c
24 -rwxr-xr-x 1 Me staff 8712 Mar 12 20:57 ex3
8 -rw-r--r-- 1 Me staff 184 Mar 12 19:53 ex3.c
0 drwxr-xr-x 3 Me staff 102 Mar 12 20:57 ex3.dSYM
My-MacBook-Pro:Exercises Me$ sw_vers
ProductName: Mac OS X
ProductVersion: 10.11.6
BuildVersion: 15G1217
My-MacBook-Pro:Exercises Me$
My-MacBook-Pro:Exercises Me$ clang --version -g
Apple LLVM version 8.0.0 (clang-800.0.42.1)
Target: x86_64-apple-darwin15.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
My-MacBook-Pro:Exercises Me$
My-MacBook-Pro:Exercises Me$ make --version
GNU Make 3.81
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
This program built for i386-apple-darwin11.3.0
My-MacBook-Pro:Exercises Me$
My-MacBook-Pro:Exercises Me$ lldb --version
lldb-360.1.70
In response to "Olaf":
LLDB Documentation
(lldb) breakpoint set --name main
(lldb) br s -n main
(lldb) b main
There is one other thread with a similar error message from 2015 on an older version of OSX, but its 'solution' does NOT work, and indeed ignores the issue by not using Make at all.
I'd like to try and avoid orthogonal or complex 'suggestions' along the lines of "Why don't you not use C, try using some other language", or "I prefer using a different debugger, so use this one" ... those won't answer the question :)

Answer 1

The b command and the breakpoint set command are quite different. b is a DWIM type command that tries as much as possible to emulate the gdb breakpoint parser's syntax. It eventually dispatches to break set with the appropriate breakpoint type.
breakpoint set -n foo creates a general "symbol name matching" breakpoint. So for instance, it will match a function called "foo" or an ObjC selector "foo" or a C++ method called "foo"... b foo dispatches to breakpoint set -n foo.
But sometimes you know you only want to set a breakpoint on class methods (C++ or Swift) in which case you can use the --method option to limit the search appropriately. Ditto for ObjC selectors and the --selector option.
In your case, that --name worked but --method didn't is correct behavior. Your main is a pure C function, not a class method.
BTW, the b is actually an lldb "regex command", see
(lldb) help command regex
for more details. You can see what the command is actually doing by turning on echoing the regex command resolution with:
(lldb) set set interpreter.expand-regex-aliases 1
then try some breakpoints:
(lldb) b main
breakpoint set --name 'main'
(lldb) b foo.c:11
breakpoint set --file 'foo.c' --line 11
etc...

Answer 2

From one person's attempt to reproduce the conditions, a valuable observation that in his installation he could get the commands to work synonymously as prescribed was helpful, and indirectly provided the solution.
I uninstalled the entire XCode module and the other supporting C development modules I had, and re-installed with fresh downloads. After that, I had the same functionality he observed.
The issue was therefore somewhere in the binary installations on my specific MacBook, perhaps due to an update not having properly applied somewhere along the way, and this was not a generic issue.