find_program works a bit different than expected

.github/workflows/cmake-multi-platform.yml

@@ -45,7 +45,6 @@ jobs:
         cmake -B ${{ steps.strings.outputs.build-output-dir }}
         cmake -B ${{ steps.strings.outputs.build-output-dir }}
         -DCMAKE_CXX_COMPILER=${{ matrix.cpp_compiler }}
         -DCMAKE_CXX_COMPILER=${{ matrix.cpp_compiler }}
         -DCMAKE_BUILD_TYPE=Release
         -DCMAKE_BUILD_TYPE=Release
-        -DCIFPP_DOWNLOAD_CCD=OFF
         -S ${{ github.workspace }}
         -S ${{ github.workspace }}
         
         
     - name: Build
     - name: Build

CMakeLists.txt

@@ -377,7 +377,7 @@ if(CIFPP_DOWNLOAD_CCD)
 		# decompress it ourselves.
 		# decompress it ourselves.
 		find_program(GUNZIP gunzip)
 		find_program(GUNZIP gunzip)
 
 
-		if(GUNZIP)
+		if(NOT GUNZIP STREQUAL "GUNZIP-NOTFOUND")
 			if(NOT EXISTS "${COMPONENTS_CIF}.gz")
 			if(NOT EXISTS "${COMPONENTS_CIF}.gz")
 				file(DOWNLOAD https://files.wwpdb.org/pub/pdb/data/monomers/components.cif.gz ${COMPONENTS_CIF}.gz
 				file(DOWNLOAD https://files.wwpdb.org/pub/pdb/data/monomers/components.cif.gz ${COMPONENTS_CIF}.gz
 					SHOW_PROGRESS STATUS CCD_FETCH_STATUS)
 					SHOW_PROGRESS STATUS CCD_FETCH_STATUS)