build: don't hardcode _libs directory in CMakeLists

The fact that pbk expects the bitcoinkernel shared library in the
_libs directory, is part of the scikit-build-core pipeline. Take
it out of the CMakeLists logic, and update callsites/pyproject.toml
to properly set the install location.

Author: stickies-v

.github/workflows/pytest.yml

@@ -31,7 +31,7 @@ jobs:
         run: |
           cmake -B build
           cmake --build build -j
-          cmake --install build --strip
+          cmake --install build --prefix build/_libs/
 
       - name: Save lib cache
         if: steps.cache-lib.outputs.cache-hit != 'true'

.github/workflows/release.yml

@@ -66,7 +66,7 @@ jobs:
         run: |
           cmake -B build ${{ matrix.cmake_args }}
           cmake --build build -j
-          cmake --install build
+          cmake --install build --prefix build/_libs/
 
       - name: Save lib cache
         if: steps.cache-lib.outputs.cache-hit != 'true'

CMakeLists.txt

@@ -2,9 +2,6 @@ cmake_minimum_required(VERSION 3.22)
 project(py-bitcoinkernel
         VERSION 0.1)
 
-# Set install prefix to be relative to the build directory
-set(CMAKE_INSTALL_PREFIX "${CMAKE_BINARY_DIR}")
-
 include(ExternalProject)
 include(GNUInstallDirs)
 
@@ -89,6 +86,6 @@ set_target_properties(bitcoinkernel PROPERTIES
 )
 
 install(FILES "${BITCOINKERNEL_PATH}"
-    DESTINATION "_libs"
+    DESTINATION "."
     COMPONENT Kernel
 )

pyproject.toml

@@ -24,7 +24,7 @@ test-extras = ["test"]
 [tool.scikit-build]
 cmake.version = "CMakeLists.txt"
 wheel.packages = ["src/pbk"]
-wheel.install-dir = "pbk"
+wheel.install-dir = "pbk/_libs"
 sdist.include = [
     "depend/bitcoin/src/univalue/lib/**",  # Otherwise this doesn't get included in the sdist
 ]