For some reason I've suddenly started having linker issues when building a clean single-driver MAME:

Code
> make -j8 SUBTARGET=mame_galaga_ SOURCES=src/mame/video/galaga.cpp
.
.
.
Compiling generated/version.cpp...
Building driver list...
Emitting mame_galaga_-Info.plist...
0 source file(s) found
36363 driver(s) found
Compiling generated/mame/mame_galaga_/drivlist.cpp...
Linking mame_galaga_64...
Undefined symbols for architecture x86_64:
  "_driver_005", referenced from:
      driver_list::s_drivers_sorted in drivlist.o
  "_driver_100lions", referenced from:
      driver_list::s_drivers_sorted in drivlist.o
  "_driver_10yard", referenced from:
      driver_list::s_drivers_sorted in drivlist.o
  "_driver_10yard85", referenced from:
      driver_list::s_drivers_sorted in drivlist.o
  "_driver_10yardj", referenced from:
      driver_list::s_drivers_sorted in drivlist.o
  "_driver_11beat", referenced from:
      driver_list::s_drivers_sorted in drivlist.o
.
.
.

And it will keep on spitting out that undefined symbol list for several minutes...

I'm 99% certain that I was able to compile MAME when I first installed Catalina. Any ideas why this might be occurring?

My mac: MacBook Pro running Catalina 10.15.1

> clang -v
Apple clang version 11.0.0 (clang-1100.0.33.12)
Target: x86_64-apple-darwin19.0.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

installed SDL version is 2.0.10

Thanks!
-Robert