Attempting to Verify using IDE 2.0 Beta 5 with build_opt.h in sketch folder results in:

arm-none-eabi-g++: error: #line: No such file or directory
arm-none-eabi-g++: error: 1: No such file or directory
Compilation error: Error: 2 UNKNOWN: exit status 1

IDE 1.18.3 with the same sketch & build_opt.h verifies without error

To Reproduce
Install IDE 2.0 Beta 5
place a build_opt.h file containing the line -DHAL_CRC_MODULE_ENABLED
attempt to verify

Expected behavior
Verification as in IDE 1.18.3

Desktop (please complete the following information):

• Windows 10 x64 Pro
• Arduino IDE version 2.0 Beta 5
• STM32 core version: 2.0.0
• Upload method: n/a

Board (please complete the following information):
Generic STM32F1 series