I am trying to install Savi-program for monitoring satellites found here via Terminal. I am developer so I have XCode installed. which gcc returns /usr/bin/gcc. Command make ARCH=macosx once in the directory is the code to execute. However, I am getting an error, saying 'X11/Xlib.h'. Where do I get 'X11/Xlib.h' so that the program installs successfully?

This is the full error:

Mains-MBP:savi1.4.9 mainuser$ make ARCH=macosx
making all in manual...
making all in manual/images...
make[2]: Nothing to be done for `all'.
making all in bin...
make[1]: Nothing to be done for `all'.
making all in maps...
make[1]: Nothing to be done for `all'.
making all in oogl...
make[1]: Nothing to be done for `all'.
making all in data...
make[1]: Nothing to be done for `all'.
making all in tcl...
tclsh mkindex.tcl
making all in src...
making all in src/include...
make[2]: Nothing to be done for `all'.
gcc -O2 -DNO_ZLIB -Wall -Wextra -Wconversion -pedantic -ansi -I./include -I/opt/X11/include   -c -o main.o main.c
In file included from main.c:38:
In file included from ./include/tcl_utils.h:40:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/tk.h:78:11: fatal error: 
      'X11/Xlib.h' file not found
#       include <X11/Xlib.h>
1 error generated.
make[2]: *** [main.o] Error 1
make[1]: *** [all] Error 2
make: *** [all] Error 2
  • 1
    Did you have installed XQuartz? Commented Jun 4, 2016 at 15:48
  • The missing source file is needed for compiling programs using the X11 graphics system common for Linux systems (which MacOS don't support natively). You do not have the needed dependencies installed on your system. Commented Jul 4, 2020 at 10:19

1 Answer 1


The instructions you quote tell you exactly what the issue is

When you type make you will be prompted to install Xcode. You can also install Xcode by typing the terminal command xcode-select --install

If your compilation fails with an Xlib not found error, install XQuartz to get X11 headers under /opt/X11, and then type:

make ARCH=macosx
  • This worked for me on a similar problem with a different program
    – jthomas
    Commented Mar 2, 2018 at 19:39

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