cmake: Include GNUInstallDirs earlier for BINDIR etc to take effect

GNUInstallDirs is what defines CMAKE_INSTALL_FULL_BINDIR and such, so
the setting in Rust.cmake didn't work.

This also makes build.rs error out if any of these aren't defined

CMakeLists.txt

@@ -24,6 +24,10 @@ if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
     set(CMAKE_BUILD_TYPE "${DEFAULT_BUILD_TYPE}")
 endif()
 
+# Set up standard directories.
+include(GNUInstallDirs)
+add_definitions(-D_UNICODE=1)
+
 include(cmake/ConfigureChecks.cmake)
 include(cmake/gettext.cmake)
 
@@ -110,18 +114,6 @@ include_directories(${CMAKE_CURRENT_BINARY_DIR})
 # Pull in our src directory for headers searches, but only quoted ones.
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -iquote ${CMAKE_CURRENT_SOURCE_DIR}/src")
 
-
-
-# Set up standard directories.
-include(GNUInstallDirs)
-add_definitions(-D_UNICODE=1
-                -DLOCALEDIR="${CMAKE_INSTALL_FULL_LOCALEDIR}"
-                -DPREFIX=L"${CMAKE_INSTALL_PREFIX}"
-                -DDATADIR=L"${CMAKE_INSTALL_FULL_DATADIR}"
-                -DSYSCONFDIR=L"${CMAKE_INSTALL_FULL_SYSCONFDIR}"
-                -DBINDIR=L"${CMAKE_INSTALL_FULL_BINDIR}"
-                -DDOCDIR=L"${CMAKE_INSTALL_FULL_DOCDIR}")
-
 # Set up the machinery around FISH-BUILD-VERSION-FILE
 # This defines the FBVF variable.
 include(Version)

cmake/Install.cmake

@@ -41,15 +41,6 @@ set(extra_confdir
     CACHE STRING "Path for extra configuration")
 
 
-corrosion_set_env_vars(${fish_rust_target}
-    "PREFIX=${prefix}"
-    # Temporary hack to propogate CMake flags/options to build.rs.
-    "CMAKE_WITH_GETTEXT=${CMAKE_WITH_GETTEXT}"
-    "DOCDIR=${CMAKE_INSTALL_FULL_DOCDIR}"
-    "DATADIR=${CMAKE_INSTALL_FULL_DATADIR}"
-    "SYSCONFDIR=${CMAKE_INSTALL_FULL_SYSCONFDIR}"
-    "BINDIR=${CMAKE_INSTALL_FULL_BINDIR}"
-)
 # These are the man pages that go in system manpath; all manpages go in the fish-specific manpath.
 set(MANUALS ${CMAKE_CURRENT_BINARY_DIR}/user_doc/man/man1/fish.1
             ${CMAKE_CURRENT_BINARY_DIR}/user_doc/man/man1/fish_indent.1

fish-rust/build.rs

@@ -8,6 +8,9 @@ fn main() {
     for key in ["DOCDIR", "DATADIR", "SYSCONFDIR", "BINDIR", "LOCALEDIR"] {
         if let Ok(val) = env::var(key) {
             // Forward some CMake config
+            if val.is_empty() {
+                panic!("{} is empty!", key);
+            }
             println!("cargo:rustc-env={key}={val}");
         }
     }