build system: Disable checking ICU libs for cross builds

ldd is used to determine the location of the ICU libs, which
does not work for cross builds.

Fixes: PYSIDE-2060
Change-Id: Idbf8c6e9239f4623b7c11c646a616ef44e8c3ecf
Reviewed-by: Shyamnath Premnadh <Shyamnath.Premnadh@qt.io>
Reviewed-by: Christian Tismer <tismer@stackless.com>
(cherry picked from commit a96676f96ae6011c26dd58567d993cebe4d9d6cf)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

4 files changed, 10 insertions, 7 deletions

diff --git a/build_scripts/main.py b/build_scripts/main.py
index daf7d2f70..d69a5324b 100644
--- a/build_scripts/main.py
+++ b/build_scripts/main.py
@@ -960,7 +960,7 @@ class PysideBuild(_build, DistUtilsCommandMixin, BuildInfoCollectorMixin):
                 _vars['dbg_postfix'] = OPTION["DEBUG"] and "_d" or ""
                 return prepare_packages_win32(self, _vars)
             else:
-                return prepare_packages_posix(self, _vars)
+                return prepare_packages_posix(self, _vars, self.is_cross_compile)
         except IOError as e:
             print('setup.py/prepare_packages: ', e)
             raise
diff --git a/build_scripts/platforms/linux.py b/build_scripts/platforms/linux.py
index b0c025bc8..bf4db5664 100644
--- a/build_scripts/platforms/linux.py
+++ b/build_scripts/platforms/linux.py
@@ -46,7 +46,7 @@ from ..utils import (copy_icu_libs, copydir, copyfile, find_files_using_glob,
 from ..versions import PYSIDE
 
 
-def prepare_standalone_package_linux(self, _vars):
+def prepare_standalone_package_linux(self, _vars, cross_build=False):
     built_modules = _vars['built_modules']
 
     constrain_modules = None
@@ -86,10 +86,11 @@ def prepare_standalone_package_linux(self, _vars):
         # Qt is built against system ICU, or in the Coin CI where ICU
         # libs are in a different directory) try to find out / resolve
         # which ICU libs are used by QtCore (if used at all) using a
-        # custom written ldd, and copy the ICU libs to the Pyside Qt
-        # dir if necessary. We choose the QtCore lib to inspect, by
+        # custom written ldd (non-cross build only), and copy the ICU
+        # libs to the Pyside Qt dir if necessary.
+        # We choose the QtCore lib to inspect, by
         # checking which QtCore library the shiboken6 executable uses.
-        if not maybe_icu_libs:
+        if not maybe_icu_libs and not cross_build:
             copy_icu_libs(self._patchelf_path, resolved_destination_lib_dir)
 
     # Set RPATH for Qt libs.
diff --git a/build_scripts/platforms/unix.py b/build_scripts/platforms/unix.py
index 904ae9c0e..ec0a8bb9c 100644
--- a/build_scripts/platforms/unix.py
+++ b/build_scripts/platforms/unix.py
@@ -74,7 +74,7 @@ def _copy_gui_executable(name, _vars=None):
     return _unix_copy_gui_executable(name, _vars)
 
 
-def prepare_packages_posix(self, _vars):
+def prepare_packages_posix(self, _vars, cross_build=False):
     executables = []
     libexec_executables = []
 
@@ -245,7 +245,7 @@ def prepare_packages_posix(self, _vars):
             if sys.platform == 'darwin':
                 prepare_standalone_package_macos(self, _vars)
             else:
-                prepare_standalone_package_linux(self, _vars)
+                prepare_standalone_package_linux(self, _vars, cross_build)
 
         if config.is_internal_shiboken_generator_build():
             # Copy over clang before rpath patching.
diff --git a/build_scripts/utils.py b/build_scripts/utils.py
index 6f44ae5c2..3772a14df 100644
--- a/build_scripts/utils.py
+++ b/build_scripts/utils.py
@@ -947,6 +947,8 @@ def find_qt_core_library_glob(lib_dir):
 # ldd for the specified platforms.
 # This has less priority because ICU libs are not used in the default
 # Qt configuration build.
+# Note: Uses ldd to query shared library dependencies and thus does not
+# work for cross builds.
 def copy_icu_libs(patchelf, destination_lib_dir):
     """
     Copy ICU libraries that QtCore depends on,