I have no idea what is going on, none of the UI libraries seem to work. I'm stumped, hopefully it's a simple mistake somewhere. Compiling with GCC on cygwin

/tmp/ccWpqqQP.o:main.c:(.text+0x3c): undefined reference to uiMultilineEntryAppend'
/tmp/ccWpqqQP.o:main.c:(.text+0x3c): relocation truncated to fit: R_X86_64_PC32 against undefined symbol uiMultilineEntryAppend' /tmp/ccWpqqQP.o:main.c:(.text+0x5c): undefined reference to uiQuit'
/tmp/ccWpqqQP.o:main.c:(.text+0x5c): relocation truncated to fit: R_X86_64_PC32 against undefined symbol uiQuit' /tmp/ccWpqqQP.o:main.c:(.text+0x90): undefined reference to uiMultilineEntryAppend'
/tmp/ccWpqqQP.o:main.c:(.text+0x90): relocation truncated to fit: R_X86_64_PC32 against undefined symbol uiMultilineEntryAppend' /tmp/ccWpqqQP.o:main.c:(.text+0xc7): undefined reference to uiInit'
/tmp/ccWpqqQP.o:main.c:(.text+0xc7): relocation truncated to fit: R_X86_64_PC32 against undefined symbol uiInit' /tmp/ccWpqqQP.o:main.c:(.text+0xee): undefined reference to uiNewWindow'
/tmp/ccWpqqQP.o:main.c:(.text+0xee): relocation truncated to fit: R_X86_64_PC32 against undefined symbol uiNewWindow' /tmp/ccWpqqQP.o:main.c:(.text+0x103): undefined reference to uiWindowSetMargined'
/tmp/ccWpqqQP.o:main.c:(.text+0x103): relocation truncated to fit: R_X86_64_PC32 against undefined symbol uiWindowSetMargined' /tmp/ccWpqqQP.o:main.c:(.text+0x108): undefined reference to uiNewVerticalBox'
/tmp/ccWpqqQP.o:main.c:(.text+0x108): relocation truncated to fit: R_X86_64_PC32 against undefined symbol uiNewVerticalBox' /tmp/ccWpqqQP.o:main.c:(.text+0x11d): undefined reference to uiBoxSetPadded'
/tmp/ccWpqqQP.o:main.c:(.text+0x11d): relocation truncated to fit: R_X86_64_PC32 against undefined symbol uiBoxSetPadded' /tmp/ccWpqqQP.o:main.c:(.text+0x12d): undefined reference to uiWindowSetChild'
/tmp/ccWpqqQP.o:main.c:(.text+0x12d): relocation truncated to fit: R_X86_64_PC32 against undefined symbol uiWindowSetChild' /tmp/ccWpqqQP.o:main.c:(.text+0x132): undefined reference to uiNewMultilineEntry'
/tmp/ccWpqqQP.o:main.c:(.text+0x132): relocation truncated to fit: R_X86_64_PC32 against undefined symbol uiNewMultilineEntry' /tmp/ccWpqqQP.o:main.c:(.text+0x156): undefined reference to uiMultilineEntrySetReadOnly'
/tmp/ccWpqqQP.o:main.c:(.text+0x156): additional relocation overflows omitted from the output
/tmp/ccWpqqQP.o:main.c:(.text+0x162): undefined reference to uiNewButton' /tmp/ccWpqqQP.o:main.c:(.text+0x17f): undefined reference to uiButtonOnClicked'
/tmp/ccWpqqQP.o:main.c:(.text+0x195): undefined reference to uiBoxAppend' /tmp/ccWpqqQP.o:main.c:(.text+0x1b1): undefined reference to uiBoxAppend'
/tmp/ccWpqqQP.o:main.c:(.text+0x1c8): undefined reference to uiTimer' /tmp/ccWpqqQP.o:main.c:(.text+0x1e1): undefined reference to uiWindowOnClosing'
/tmp/ccWpqqQP.o:main.c:(.text+0x1ed): undefined reference to uiControlShow' /tmp/ccWpqqQP.o:main.c:(.text+0x1f2): undefined reference to uiMain'
collect2: error: ld returned 1 exit status
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