Length less than zero error when importing debug symbols

[jeffythedragonslayer]

Steps to recreate:

• First clone this repo: https://github.com/jeffythedragonslayer/snes-pal-ntsc-detector
• In build.bat, add -debug-info after the .list but before the .asm file in the call to cl65
• Then build
• Open the ROM in Mesen-SX and open the debugger
• Then import labels and select the .cpu.sym file

[jeffythedragonslayer]

I renamed the .cpu.sym file to a .dbg file and 0 labels were imported successfully, instead of the unexpected error

[jeffythedragonslayer]

moving this to the Mesen-SX repo