Users have trouble overriding the blocksize/patchpaddingalign parameters for UnrealPak from UAT commandlines.
We're using stock UE5.1 (from the launcher) and the old .pak format. I was hoping we could use the commandline option and avoid changing engine code. I tried passing -AdditionalPakOptions="-patchpaddingalign=1048576" to RunUAT.bat, but unfortunately it doesn't seem to work.I think what's happening is that UAT's UnrealPak commandline ends up as:UnrealPak.exe MyProject.uproject [...] -patchpaddingalign=2048 [...] -patchpaddingalign=1048576The first patchpaddingalign is the one from GetPlatformPakCommandLine, the second is from my AdditionalPakOptions. It turns out that the commandline parser always takes the first value it finds, so there's no way to override UAT's platform default patchpaddingalign with commandline options.For the old .pak format, it looks like we either have to modify the UAT code as described above, or run UnrealPak directly instead of through UAT.It looks like using -iostore will hit the same issue, as -blocksize gets overridden by -patchpaddingalign. Luckily there's a workaround; there's a parameter called -iostorepatchpaddingalign, which isn't set by UAT and overrides all the other alignment and blocksize options. I think that's the way to go if you're using -iostore and don't want to edit the engine.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-272843 in the post.