macOS Monterey 12.1, broken builds after update.

[SPlatten]

I'm fast getting to the opinion that upgrading the operating system is a bad idea, I previously had a working development system.

iMAC (Retina 5K, 27-inch, Late 2015)
Processor 4 GHz Quad-Core Intel Core i7 
Memory 16 GB 1867 MHz DDR3
Graphics AMD Radeon R9 M395X 4 GB

I've just tried to build a library that was previously ok, no changes to the source, now it will not build because unistd.h file not found.

Other issues, unknown type name time_t

My project is built using:

Qt Creator 4.15.0-beta2 (4.14.83)
Based on Qt 5.15.2 (Clang 11.0 (Apple), 64 bit)
Built on Mar 24 2021 04:43:31
From revision 460d446c61

How can I fix this?

Edit, I've just performed:

brew update
brew upgrade

no different, same problem. Using getInfo on the file unistd.h in finder I then copied the path into the include:

#include </Library/Developer/CommandLineTools/SDKs/MacOSX11.3.sdk/System/Library/Frameworks/Kernel.framework/Versions/A/Headers/sys/unistd.h>

[SPlatten]

@artwaw , I've fixed the build, by deleting the contents of the build folder including hidden files.

[artwaw]

@SPlatten Did you also updated the Xcode? Those header files are usually included in the Xcode, it might be that you just need to update command line tools/developer path after the update. I have them for every platform in Xcode 13.1 (as I had them in previous versions).

[SPlatten]

@artwaw Xcode is version 13.2.1, how do I update it?

[artwaw]

@SPlatten I just saw your include, please verify the path. For me it is
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.1.sdk/usr/include
I just double checked, if there is missing dev path or command line tools, Xcode would complain when running clang/cmake. So that you already have properly set.

But please, verify that path for the include.

[SPlatten]

@artwaw , on my system, it also exists in:

/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include

Which doesn't match yours exactly.

[artwaw]

@SPlatten That is probably more stable path, since MacOSX12.1.sdk is the symlink.

[SPlatten]

@artwaw , although, I still can't make the project:

/Users/sy/Qt/5.15.2/clang_64/mkspecs/features/mac/sdk.mk:22: warning: *** ^.  Stop.

[SPlatten]

@artwaw , I've fixed the build, by deleting the contents of the build folder including hidden files.

[artwaw]

@SPlatten I don't know, really. It works on my iMac. I would, however, recommend to reinstall the command line tools - this would trigger reinstallation of the SDK