It sounds like your builds are not correctly specifying the SDK gcc is to use. There are a number of ways you can do this, either by pass it via a compiler flag, by running the complication through xcrun, or by setting the SDKROOT variables to the required path.
Cheers Chris > On 7 Feb 2021, at 9:25 pm, Carlo Tambuatco <[email protected]> wrote: > > I don’t know if this is a result of updating to the latest macports gcc9, or > the update of XCode, but > all of a sudden when I try to build my C++ program which includes <cstdio> I > get this strange > chain reaction of errors. > > In file included from /opt/local/include/gcc9/c++/ext/string_conversions.h:41, > from /opt/local/include/gcc9/c++/bits/basic_string.h:6493, > from /opt/local/include/gcc9/c++/string:55, > from /opt/local/include/gcc9/c++/bits/locale_classes.h:40, > from /opt/local/include/gcc9/c++/bits/ios_base.h:41, > from /opt/local/include/gcc9/c++/ios:42, > from /opt/local/include/gcc9/c++/ostream:38, > from /opt/local/include/gcc9/c++/iostream:39, > from ../../standard_includes.h:1, > from E2.5.2.cpp:1: > /opt/local/include/gcc9/c++/cstdlib:75:15: fatal error: stdlib.h: No such > file or directory > 75 | #include_next <stdlib.h> > > > From my makefile this seems to be the offending includes statement: > > #include <iostream> > #include <cstdio> > > > I’ve googled and it seems that it can’t find stdlib.h, even though it is on > my CPATH environment variable: > > export > CPATH=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include:/usr/local/include:/opt/local/include:/usr/local/dart-sdk/include:/Library/Frameworks/R.framework/Resources/include >
