A 32-bit ASM file can turn into an empty binary file in certain cases (compiled with MSVC).
MASM/ML produces a ".text$mn" section instead of the ".text", which makes obj2bin generate an empty binary file.
The problem didn't occur with our 16-bit artifacts (16-bit stubs, bootsectors...), because their object files all have similar sections pattern: the ".text" section and empty ".text$mn" section, which didn't matter since it is empty.
On the contrary, the .text$mn section(s) aren't empty for 32-bit stubs.
Dmitry Borisov