From: Viktor Szakats <commit@vsz.me>
Date: Tue, 22 Apr 2025 08:36:16 +0000 (+0200)
Subject: cmake: avoid 'target is imported but not globally visible' when consuming libcurl... 
X-Git-Tag: curl-8_14_0~241
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e5a965b676fe6ad27d7e1f9aa31b4869c99f2bac;p=thirdparty%2Fcurl.git

cmake: avoid 'target is imported but not globally visible' when consuming libcurl with old cmake

Fixes:
```
CMake Error at bld-curl/_pkg/lib/cmake/CURL/CURLConfig.cmake:62 (add_library):
  add_library cannot create ALIAS target "CURL::libcurl" because target
  "CURL::libcurl_shared" is imported but not globally visible.
Call Stack (most recent call first):
  CMakeLists.txt:39 (find_package)
```

tests/cmake reproducer (requires #16973):
```shell
export CMAKE_CONSUMER=/path/to/CMake-3.12.0/bin/cmake
./test.sh find_package
```

I don't understand what this error says, why it happens in certain CMake
versions, and why a workaround is necessary for what seems like
a standard export/consume configuration. This patch is based on internet
suggestions and other projects ending up with this workaround.

Cherry-picked from #16973
Closes #17140
---

diff --git a/CMake/curl-config.cmake.in b/CMake/curl-config.cmake.in
index a4df052c2a..4788afb8c7 100644
--- a/CMake/curl-config.cmake.in
+++ b/CMake/curl-config.cmake.in
@@ -35,6 +35,9 @@ include("${CMAKE_CURRENT_LIST_DIR}/@TARGETS_EXPORT_NAME@.cmake")
 
 # Alias for either shared or static library
 if(NOT TARGET @PROJECT_NAME@::libcurl)
+  if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.11 AND CMAKE_VERSION VERSION_LESS 3.18)
+    set_target_properties(@PROJECT_NAME@::@LIB_SELECTED@ PROPERTIES IMPORTED_GLOBAL TRUE)
+  endif()
   add_library(@PROJECT_NAME@::libcurl ALIAS @PROJECT_NAME@::@LIB_SELECTED@)
 endif()