The current GIT version pushes two extensive updates
All option processing in the system now uses library(option) or the C PL_scan_options(). This implies that all option processing deals with both lists and dicts. A few places that allowed for repeating options, e.g., filter(+Filter) in archive_open/4 have been changed to allow for filters(+List) with a backward compatibility emulation that warns on multiple filter(+Filter) options. These changes try to make option processing more transparent and uniform, ultimately dealing with the fact that Prolog defined predicates handle options as first wins, while C (and ISO) use last wins.
On Windows, canonical file name handling has been changed to use be case preserving, i.e., use the case as it appears on disk. Before this, Prolog communicated all file names as lower case.
Both should have none or very limited impact on user programs. Please report issues!