Fix Ogre build failure on Xcode 26 (xcodebuild -n removed)

[idesign0]

Problem

Xcode 26 removed the -n flag from xcodebuild. Ogre v1.12.10's CMakeLists.txt uses execute_process with a shell pipe to detect the macOS SDK path:

execute_process(
  COMMAND xcodebuild -version -sdk "${XCODE_ATTRIBUTE_SDKROOT}" Path | head -n 1
  OUTPUT_VARIABLE CMAKE_OSX_SYSROOT)

CMake's execute_process does not use a shell, so | head -n 1 is passed as literal arguments to xcodebuild. With Xcode 26, the -n argument is rejected:

xcodebuild: error: option '-n' is no longer supported
Usage: xcodebuild [-project <projectname>] [[-target <targetname>]...|-alltargets] [-configuration <configurationname>] ...
       xcodebuild [-project <projectname>] -scheme <schemeName> [-destination <destinationspecifier>]...
       ...

The full usage page is captured into CMAKE_OSX_SYSROOT, corrupting it with embedded newlines and breaking all subsequent compiler invocations:

/bin/sh: -c: line 0: unexpected EOF while looking for matching `"'
/bin/sh: -c: line 1: syntax error: unexpected end of file

Fix

Add patches/0007-fix-xcodebuild-n-xcode26.patch which replaces the broken call with:

execute_process(COMMAND xcrun --sdk macosx --show-sdk-path
                OUTPUT_VARIABLE CMAKE_OSX_SYSROOT)

xcrun --show-sdk-path is the correct modern replacement and works across all supported Xcode versions.

Fyi, @traversaro — this may affect RoboStack/conda-forge builds of rviz on macOS with Xcode 26. The same bug exists in gz_ogre_next_vendor (ogre-next v2.3.3, same execute_process pipe pattern) — fix incoming there too.

[traversaro]

Fyi, @traversaro — this may affect RoboStack/conda-forge builds of rviz on macOS with Xcode 26. The same bug exists in gz_ogre_next_vendor (ogre-next v2.3.3, same execute_process pipe pattern) — fix incoming there too.

Thanks for the mention! Indeed, that may be the case, fyi @wep21 @Tobias-Fischer.

[mergify]

Tick the box to add this pull request to the merge queue (same as @mergifyio queue).

• Queue this pull request