cmake: searching across directories for config files #32938

1. 
   fanquake commented at 11:39 am on July 10, 2025: member

   This can be recreated on at least macOS, due to #32707.

   If there are two checkouts of the source, the build in one directory, can fail to configure, because of files in the other directory:

    0git clone https://github.com/bitcoin/bitcoin/ bitcoin_a
    1git clone https://github.com/bitcoin/bitcoin/ bitcoin_b
    2
    3cd bitcoin_a
    4make -C depends HOST=x86_64-w64-mingw32
    5# fails to build libevent (#32707)
    6cd ../bitcoin_b
    7# fails to configure, because of the libevent config files (for a different target) in the other checkout
    8cmake -B build
    9<snip>
   10-- Performing Test NO_DIAGNOSTICS_BOOST_NO_CXX98_FUNCTION_BASE
   11-- Performing Test NO_DIAGNOSTICS_BOOST_NO_CXX98_FUNCTION_BASE - Failed
   12CMake Error at /Users/xxx/bitcoin_a/depends/work/build/x86_64-w64-mingw32/libevent/2.1.12-stable-f0fd46dc234/build/LibeventConfig.cmake:75 (message):
   13  Your libevent library does not contain a pthreads component!
   14
   15  The valid components are core, extra, pthreads and openssl.
   16Call Stack (most recent call first):
   17  /Users/xxx/bitcoin_a/depends/work/build/x86_64-w64-mingw32/libevent/2.1.12-stable-f0fd46dc234/build/LibeventConfig.cmake:90 (no_component_msg)
   18  cmake/module/FindLibevent.cmake:54 (find_package)
   19  CMakeLists.txt:416 (find_package)
   

2. fanquake added the label Build system on Jul 10, 2025
3. 
   hebasto commented at 1:13 pm on July 10, 2025: member

   Could you please confirm whether the following patch helps:

    0--- a/depends/patches/libevent/cmake_fixups.patch
    1+++ b/depends/patches/libevent/cmake_fixups.patch
    2@@ -7,7 +7,7 @@ cmake: set minimum version to 3.5
    3  #
    4  
    5 -cmake_minimum_required(VERSION 3.1 FATAL_ERROR)
    6-+cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
    7++cmake_minimum_required(VERSION 3.15 FATAL_ERROR)
    8  
    9  if (POLICY CMP0054)
   10      cmake_policy(SET CMP0054 NEW)
   

   ?

4. 
   fanquake commented at 4:24 pm on July 10, 2025: member

   That seems to fix it. I haven’t tested extensively though.

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fanquake hebasto

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