Jailbroken and Can’t install .deb files

[Nacumoe 1]

Everything I have downloaded from here keeps saying the process has forked and I my iPhone is jailbroken what should I try next

The process has forked and you cannot use this CoreFoundation functionality safely. You MUST exec().

Break on __THE_PROCESS_HAS_FORKED_AND_YOU_CANNOT_USE_THIS_COREFOUNDATION_FUNCTIONALITY___YOU_MUST_EXEC__() to debug.

The process has forked and you cannot use this CoreFoundation functionality safely. You MUST exec().

Break on

[Whack57 0]

Thank you. Have a good day