Try FindPkgConfig to find modules before going manual

cmake/modules/FindGnuTLS.cmake

@@ -30,6 +30,19 @@ This module will set the following variables in your project:
 
 #]=======================================================================]
 
+include(FindPkgConfig)
+if(PKG_CONFIG_FOUND)
+    pkg_check_modules(PkgGnuTLS IMPORTED_TARGET GLOBAL QUIET gnutls)
+    pkg_check_modules(PkgGnuTLSDane IMPORTED_TARGET GLOBAL QUIET gnutls-dane)
+endif()
+
+if(PkgGnuTLS_FOUND AND PkgGnuTLSDane_FOUND)
+  set(GNUTLS_INCLUDE_DIR ${PkgGnuTLS_INCLUDE_DIRS} $PkgGnuTLSDane_INCLUDE_DIRS})
+  set(NETTLE_LIBRARIES ${PkgGnuTLS_LIBRARIES} ${PkgGnuTLSDane_LIBRARIES})
+  set(NETTLE_VERSION ${PkgGnuTLS_VERSION})
+  add_library(GnuTLS::GnuTLS ALIAS PkgConfig::PkgGnuTLS)
+  add_library(GnuTLS::Dane ALIAS PkgConfig::PkgGnuTLSDane)
+else()
   find_path(GNUTLS_INCLUDE_DIR gnutls/gnutls.h
     HINTS
     "${GNUTLS_DIR}"
@@ -75,6 +88,7 @@ if (GNUTLS_INCLUDE_DIR AND GNUTLS_LIBRARY AND GNUTLS_DANE_LIBRARY)
   endif()
   
   list(APPEND GNUTLS_LIBRARIES "${GNUTLS_LIBRARY}" "${GNUTLS_DANE_LIBRARY}")
+endif()
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(GnuTLS

cmake/modules/FindLibevent2.cmake

@@ -28,6 +28,17 @@ This module will set the following variables in your project:
 
 #]=======================================================================]
 
+include(FindPkgConfig)
+if(PKG_CONFIG_FOUND)
+    pkg_check_modules(PkgLibevent IMPORTED_TARGET GLOBAL QUIET libevent>=2)
+endif()
+
+if(PkgLibevent_FOUND)
+  set(LIBEVENT2_INCLUDE_DIR ${PkgLibevent_INCLUDE_DIRS})
+  set(LIBEVENT2_LIBRARIES ${PkgLibevent_LIBRARIES})
+  set(LIBEVENT2_VERSION ${PkgLibevent_VERSION})
+  add_library(Libevent2::Libevent_core ALIAS PkgConfig::PkgLibevent)
+else()
   find_path(LIBEVENT2_INCLUDE_DIR event2/event.h
     HINTS
     "${LIBEVENT2_DIR}"
@@ -59,6 +70,7 @@ if (LIBEVENT2_INCLUDE_DIR AND LIBEVENT2_LIBRARY)
   endif()
   
   list(APPEND LIBEVENT2_LIBRARIES "${LIBEVENT2_LIBRARY}")
+endif()
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(Libevent2

cmake/modules/FindLibidn2.cmake

@@ -28,6 +28,17 @@ This module will set the following variables in your project:
 
 #]=======================================================================]
 
+include(FindPkgConfig)
+if(PKG_CONFIG_FOUND)
+    pkg_check_modules(PkgLibIdn2 IMPORTED_TARGET GLOBAL libidn2)
+endif()
+
+if(PkgLibIdn2_FOUND)
+  set(LIBIDN2_INCLUDE_DIR ${PkgLibIdn2_INCLUDE_DIRS})
+  set(LIBIDN2_LIBRARIES ${PkgLibIdn2_LIBRARIES})
+  set(LIBIDN2_VERSION ${PkgLibIdn2_VERSION})
+  add_library(Libidn2::Libidn2 ALIAS PkgConfig::PkgLibIdn2)
+else()
   find_path(LIBIDN2_INCLUDE_DIR idn2.h
     HINTS
       "${LIBIDN2_DIR}"
@@ -56,9 +67,10 @@ if (LIBIDN2_INCLUDE_DIR AND LIBIDN2_LIBRARY)
       file(STRINGS "${LIBIDN2_INCLUDE_DIR}/idn2.h" LIBIDN2_H REGEX "^#define IDN2_VERSION ")
       string(REGEX REPLACE "^.*IDN2_VERSION \"([0-9.]+)\".*$" "\\1" LIBIDN2_VERSION "${LIBIDN2_H}")
     endif ()
-endif()
 
     list(APPEND LIBIDN2_LIBRARIES "${LIBIDN2_LIBRARY}")
+  endif()
+endif()
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(Libidn2

cmake/modules/FindLibunbound.cmake

@@ -28,6 +28,17 @@ This module will set the following variables in your project:
 
 #]=======================================================================]
 
+include(FindPkgConfig)
+if(PKG_CONFIG_FOUND)
+    pkg_check_modules(PkgLibunbound IMPORTED_TARGET GLOBAL QUIET libunbound)
+endif()
+
+if(PkgLibunbound_FOUND)
+  set(LIBUNBOUND_INCLUDE_DIR ${PkgLibunbound_INCLUDE_DIRS})
+  set(LIBUNBOUND_LIBRARIES ${PkgLibunbound_LIBRARIES})
+  set(LIBUNBOUND_VERSION ${PkgLibunbound_VERSION})
+  add_library(Libunbound::Libunbound ALIAS PkgConfig::PkgLibunbound)
+else()
   find_path(LIBUNBOUND_INCLUDE_DIR unbound.h
     HINTS
     "${LIBUNBOUND_DIR}"
@@ -80,6 +91,7 @@ if (LIBUNBOUND_INCLUDE_DIR AND LIBUNBOUND_LIBRARY)
   endif()
   
   list(APPEND LIBUNBOUND_LIBRARIES "${LIBUNBOUND_LIBRARY}")
+endif
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(Libunbound

cmake/modules/FindLibuv.cmake

@@ -28,6 +28,17 @@ This module will set the following variables in your project:
 
 #]=======================================================================]
 
+include(FindPkgConfig)
+if(PKG_CONFIG_FOUND)
+    pkg_check_modules(PkgLibuv IMPORTED_TARGET GLOBAL QUIET libuv)
+endif()
+
+if(PkgLibuv_FOUND)
+  set(LIBUV_INCLUDE_DIR ${PkgLibuv_INCLUDE_DIRS})
+  set(LIBUV_LIBRARIES ${PkgLibuv_LIBRARIES})
+  set(LIBUV_VERSION ${PkgLibuv_VERSION})
+  add_library(Libuv::Libuv ALIAS PkgConfig::PkgLibuv)
+else()
   find_path(LIBUV_INCLUDE_DIR uv.h
     HINTS
     "${LIBUV_DIR}"
@@ -63,6 +74,7 @@ if (LIBUV_INCLUDE_DIR AND LIBUV_LIBRARY)
   endif()
   
   list(APPEND LIBUV_LIBRARIES "${LIBUV_LIBRARY}")
+endif()
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(Libuv

cmake/modules/FindNettle.cmake

@@ -30,6 +30,19 @@ This module will set the following variables in your project:
 
 #]=======================================================================]
 
+include(FindPkgConfig)
+if(PKG_CONFIG_FOUND)
+    pkg_check_modules(PkgNettle IMPORTED_TARGET GLOBAL nettle)
+    pkg_check_modules(PkgHogweed IMPORTED_TARGET GLOBAL QUIET hogweed)
+endif()
+
+if(PkgNettle_FOUND AND PkHogweed_FOUND)
+  set(NETTLE_INCLUDE_DIR ${PkgNettle_INCLUDE_DIRS} ${PkgHogweed_INCLUDE_DIRS})
+  set(NETTLE_LIBRARIES ${PkgNettle_LIBRARIES} ${PkgHogweed_LIBRARIES})
+  set(NETTLE_VERSION ${PkgNettle_VERSION})
+  add_library(Nettle::Nettle ALIAS PkgConfig::PkgNettle)
+  add_library(Nettle::Hogweed ALIAS PkgConfig::PkgHogweed)
+else()
   find_path(NETTLE_INCLUDE_DIR nettle/version.h
     HINTS
     "${NETTLE_DIR}"
@@ -85,6 +98,7 @@ if (NETTLE_INCLUDE_DIR AND NETTLE_LIBRARY AND HOGWEED_LIBRARY)
   endif()
   
   list(APPEND NETTLE_LIBRARIES "${NETTLE_LIBRARY}" "${HOGWEED_LIBRARY}")
+endif()
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(Nettle