depends: always install capnp to /lib

On some systems, capnp would be installed into `lib64`, I
assume due to the use of GNUInstallDirs, however all other libs we build
in depends, go into lib/. Rather than adding lib64/ to the pkg-config
and link flags, I opted for always installing into lib/.

Co-authored-by: Ryan Ofsky <[email protected]>

Author: fanquake

depends/packages/capnp.mk

@@ -5,10 +5,15 @@ $(package)_download_file=$(native_$(package)_download_file)
 $(package)_file_name=$(native_$(package)_file_name)
 $(package)_sha256_hash=$(native_$(package)_sha256_hash)
 
+# Hardcode library install path to "lib" to match the PKG_CONFIG_PATH
+# setting in depends/config.site.in, which also hardcodes "lib".
+# Without this setting, cmake by default would use the OS library
+# directory, which might be "lib64" or something else, not "lib", on multiarch systems.
 define $(package)_set_vars :=
-$(package)_config_opts := -DBUILD_TESTING=OFF
-$(package)_config_opts += -DWITH_OPENSSL=OFF
-$(package)_config_opts += -DWITH_ZLIB=OFF
+  $(package)_config_opts := -DBUILD_TESTING=OFF
+  $(package)_config_opts += -DWITH_OPENSSL=OFF
+  $(package)_config_opts += -DWITH_ZLIB=OFF
+  $(package)_config_opts += -DCMAKE_INSTALL_LIBDIR=lib/
 endef
 
 define $(package)_config_cmds