root@ubunt:/hydra# make
cd hydra-gtk && ./make_xhydra.sh
Trying to compile xhydra now (hydra gtk gui) - dont worry if this fails, this is really optional ...
Error: could not compile. Analyse this:
callbacks.c: In function ‘popen_re_unbuffered’:
callbacks.c:532: warning: format not a string literal and no format arguments
callbacks.c: In function ‘on_btnSave_clicked’:
callbacks.c:668: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result
In function ‘open’,
    inlined from ‘on_btnSave_clicked’ at callbacks.c:666:
/usr/include/bits/fcntl2.h:51: error: call to ‘__open_missing_mode’ declared with attribute error: open with O_CREAT in second argument needs 3 arguments
In function ‘snprintf’,
    inlined from ‘hydra_get_options’ at callbacks.c:247:
/usr/include/bits/stdio2.h:65: warning: call to __builtin___snprintf_chk will always overflow destination buffer
make[3]: *** [callbacks.o] Error 1
make[2]: *** [all-recursive] Error 1
make[1]: *** [all-recursive-am] Error 2

Do not worry, as I said, xhydra is really optional. ./hydra is ready to go!

Now type make install

root@ubunt:/hydra# make install
test -e hydra.exe && touch Makefile || strip hydra pw-inspector
make: [strip] Error 1 (ignored)
test -e hydra.exe && strip hydra.exe pw-inspector.exe || touch hydra
test -e xhydra && strip xhydra || touch Makefile
test -e hydra.exe && touch Makefile || cp hydra pw-inspector /usr/local/bin && cd /usr/local/bin && chmod 755 hydra pw-inspector
test -e hydra.exe && cp hydra.exe pw-inspector.exe /usr/local/bin && cd /usr/local/bin && chmod 755 hydra.exe pw-inspector.exe || touch Makefile
test -e xhydra && cp xhydra /usr/local/bin && cd /usr/local/bin && chmod 755 xhydra
make: [install] Error 1 (ignored)