Fix source build on aarch64/homebrew

Cargo.toml

@@ -27,7 +27,7 @@ members = ["proj-sys"]
 default = ["geo-types"]
 bundled_proj = [ "proj-sys/bundled_proj" ]
 pkg_config = [ "proj-sys/pkg_config" ]
-network = ["reqwest"]
+network = ["reqwest", "proj-sys/network"]
 
 [dev-dependencies]
 approx = "0.3"

proj-sys/Cargo.toml

@@ -24,6 +24,7 @@ nobuild = []
 bundled_proj = []
 # `pkg_config` feature is deprecated and does nothing
 pkg_config = []
+network = []
 
 [package.metadata.docs.rs]
 features = [ "nobuild" ] # This feature will be enabled during the docs.rs build

proj-sys/build.rs

@@ -1,6 +1,6 @@
 use flate2::read::GzDecoder;
-use std::fs::File;
 use std::env;
+use std::fs::File;
 use std::path::PathBuf;
 use tar::Archive;
 
@@ -20,6 +20,13 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         .probe("proj")
         .map(|pk| {
             eprintln!("found acceptable libproj already installed at: {:?}", pk.link_paths[0]);
+            if cfg!(feature = "network") {
+                // Generally, system proj installations have been built with tiff support
+                // allowing for network grid interaction. If this proves to be untrue
+                // could we try to determine some kind of runtime check and fall back
+                // to building from source?
+                eprintln!("assuming existing system libproj installation has network (tiff) support");
+            }
             if let Ok(val) = &env::var("_PROJ_SYS_TEST_EXPECT_BUILD_FROM_SRC") {
                 if val != "0" {
                     panic!("for testing purposes: existing package was found, but should not have been");
@@ -91,6 +98,16 @@ fn build_from_source() -> Result<std::path::PathBuf, Box<dyn std::error::Error>>
     config.define("BUILD_PROJINFO", "OFF");
     config.define("BUILD_PROJSYNC", "OFF");
     config.define("ENABLE_CURL", "OFF");
+
+    let enable_tiff = cfg!(feature="network");
+    if enable_tiff {
+        eprintln!("enabling tiff support");
+        config.define("ENABLE_TIFF", "ON");
+    } else {
+        eprintln!("disabling tiff support");
+        config.define("ENABLE_TIFF", "OFF");
+    }
+
     let proj = config.build();
     // Tell cargo to tell rustc to link libproj, and where to find it
     // libproj will be built in $OUT_DIR/lib
@@ -105,6 +122,8 @@ fn build_from_source() -> Result<std::path::PathBuf, Box<dyn std::error::Error>>
         "cargo:rustc-link-search=native={}",
         proj.join("lib").display()
     );
+
+    // This is producing a warning - this directory doesn't exist (on aarch64 anyway)
     println!(
         "cargo:rustc-link-search={}",
         &out_path.join("lib64").display()
@@ -113,9 +132,34 @@ fn build_from_source() -> Result<std::path::PathBuf, Box<dyn std::error::Error>>
         "cargo:rustc-link-search={}",
         &out_path.join("build/lib").display()
     );
+
     // The PROJ library needs SQLite and the C++ standard library.
     println!("cargo:rustc-link-lib=dylib=sqlite3");
-    println!("cargo:rustc-link-lib=dylib=tiff");
+
+    if enable_tiff {
+        // On platforms like apples aarch64, users are likely to have installed libtiff with homebrew,
+        // which isn't in the default search path, so try to determine path from pkg-config
+        match pkg_config::Config::new()
+            .atleast_version("4.0")
+            .probe("libtiff-4")
+        {
+            Ok(pk) => {
+                eprintln!(
+                    "found acceptable libtiff installed at: {:?}",
+                    pk.link_paths[0]
+                );
+                println!("cargo:rustc-link-search=native={:?}", pk.link_paths[0]);
+            }
+            Err(err) => {
+                // pkg-config might not even be installed. Let's try to stumble forward
+                // to see if the build succeeds regardless, e.g. if libtiff is installed
+                // in some default search path.
+                eprintln!("Failed to find libtiff with pkg-config: {}", err);
+            }
+        }
+        println!("cargo:rustc-link-lib=dylib=tiff");
+    }
+
     if cfg!(target_os = "linux") {
         println!("cargo:rustc-link-lib=dylib=stdc++");
     } else if cfg!(target_os = "macos") {