graphite2 install fails

[ryancclodfelter@…]

sw_vers

ProductName:	 Mac OS X
ProductVersion:	10.11
BuildVersion:	15A284

MacPorts 2.3.4

Trying to install xymon-client. Was able to install almost all the dependencies for the xymon-client port, but it install graphite2 fails.

Checking the log file, looks like it fails on this line:

:info:build /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__config:23:10: fatal error: 'unistd.h' file not found
:info:build #include <unistd.h>
:info:build          ^
:info:build 1 error generated.

Running the command xcode-select -p shows that I have xcode command line tools installed: "/Applications/Xcode.app/Contents/Developer" However, when running sudo port install xymon-client, it gives me a warning message saying that it might not be installed...

Warning: The Xcode Command Line Tools don't appear to be installed; most ports will likely fail to build.
Warning: Install them by running `xcode-select --install'.

[ryandesign (Ryan Carsten Schmidt)]

xcode-select -p does not show whether you have the command line tools installed. It only shows which developer directory is selected.

The solution is to install the Xcode command line tools by running xcode-select --install.

[ryandesign (Ryan Carsten Schmidt)]

Has duplicates #49457, #49531, #49612, #50241, #51433.