“One last build” generally isn’t enough because software might have many issues, including:
— Dependencies on other 32-bit libraries that have not changed.
— Dependencies on entire OS frameworks that have not migrated to 64-bit (and Apple has at least one of these).
— Having a “plug-in” feature, whereby cherished plug-ins have not all migrated to 64-bit so the user must then choose a 64-bit subset.
— Any number of problems in the code itself, such as improper assumptions made about the sizes of data structures or creative solutions that only made sense on 32-bit platforms. After a simple recompile, the code may crash in places or consume much more memory. Floating-point values may produce subtly different results, creating issues all over the place.
— Dependencies on other 32-bit libraries that have not changed.
— Dependencies on entire OS frameworks that have not migrated to 64-bit (and Apple has at least one of these).
— Having a “plug-in” feature, whereby cherished plug-ins have not all migrated to 64-bit so the user must then choose a 64-bit subset.
— Any number of problems in the code itself, such as improper assumptions made about the sizes of data structures or creative solutions that only made sense on 32-bit platforms. After a simple recompile, the code may crash in places or consume much more memory. Floating-point values may produce subtly different results, creating issues all over the place.