Hello, When installing Cygwin I tried installing zsh from the source, and the builtin.c module ​was not compiling. Here ​​ the output from make: rm -f libzsh-5.0.2.dll gcc -s -shared -Wl,--export-all-symbols -o libzsh-5.0.2.dll `cat stamp-modobjs` -ldl -lncursesw -lrt -lm -lc builtin.o:builtin.c:(.text+0xa98c): undefined reference to `cygwin_conv_to_posix_path' builtin.o:builtin.c:(.text+0xa98c): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `cygwin_conv_to_posix_path' /usr/lib/gcc/x86_64-pc-cygwin/4.8.1/../../../../x86_64-pc-cygwin/bin/ld: builtin.o: bad reloc address 0x8 in section `.data' collect2: error: ld returned 1 exit status Makefile:230: recipe for target `libzsh-5.0.2.dll' failed make[1]: *** [libzsh-5.0.2.dll] Error 1 make[1]: Leaving directory `/zsh-5.0.2/Src' I ​ looked up the missing function, and cygwin_conv_to_posix_path() function was deprecated and replaced with cygwin_conv_path(). In builtins.c:cd_do_chdir()​ ​I fixed it with: #ifndef _SYS_CYGWIN_H void cygwin_conv_path(cygwin_conv_path_t what, const void * from, void * to, size_t size); #endif cygwin_conv_path (CCP_WIN_A_TO_POSIX | CCP_RELATIVE, dest, buf, PATH_MAX);​ ​ dest = buf;​ ​There's still some comptests failing when running make check, but at least now it's compiling without errors​. -- ~ Ed ​gar​