wheels: force static libffi in build

- only build static libffi
- improve resilience of cibw environment variables

.github/workflows/wheels.yml

@@ -93,14 +93,14 @@ jobs:
           CIBW_BEFORE_ALL: bash ./.github/workflows/wheels/cibw_before_all.sh
           CIBW_ENVIRONMENT: >
             OPTFLAGS=-O3
-            PKG_CONFIG_PATH=./ffi/pfx/lib/pkgconfig
-            PATH="$PWD/bison/src:$PATH"
+            PKG_CONFIG_PATH={project}/ffi/pfx/lib/pkgconfig
+            PATH="{project}/bison/src:$PATH"
             CMAKE_ARGS="-DCMAKE_BUILD_TYPE=Release"
           CIBW_ENVIRONMENT_MACOS: >
             OPTFLAGS=-O3
-            PKG_CONFIG_PATH=./ffi/pfx/lib/pkgconfig
+            PKG_CONFIG_PATH={project}/ffi/pfx/lib/pkgconfig
             MACOSX_DEPLOYMENT_TARGET=11
-            PATH="$PWD/bison/src:$PATH"
+            PATH="{project}/bison/src:$PATH"
             CMAKE_ARGS="-DCMAKE_BUILD_TYPE=Release"
           CIBW_BEFORE_BUILD: bash ./.github/workflows/wheels/cibw_before_build.sh
           CIBW_TEST_COMMAND: python3 {project}/tests/pyosys/run_tests.py

.github/workflows/wheels/cibw_before_all.sh

@@ -29,9 +29,7 @@ fi
 	set -e -x
 	cd ffi
 	## Ultimate libyosys.so will be shared, so we need fPIC for the static libraries
-	CFLAGS=-fPIC CXXFLAGS=-fPIC ./configure --prefix=$PWD/pfx
+	LDFLAGS=-fPIC CFLAGS=-fPIC CXXFLAGS=-fPIC ./configure --prefix=$PWD/pfx --enable-static --disable-shared
 	make clean
 	make install -j$(getconf _NPROCESSORS_ONLN 2>/dev/null || sysctl -n hw.ncpu)
-	## Forces static library to be used in all situations
-	sed -i.bak 's@-L${toolexeclibdir} -lffi@${toolexeclibdir}/libffi.a@' ./pfx/lib/pkgconfig/libffi.pc
 )