fails to build on debian sid

Hi, Building ada-url on debian sid fails. Running the following commands: ```sh git clone --depth=1 https://github.com/ada-url/rust.git ada-url cd ada-url cargo build ``` <details> <summary>Produces the following output:</summary> ``` Compiling ada-url v2.2.1 (/ada-url) The following warnings were emitted during compilation: warning: ada-url@2.2.1: In file included from ./deps/ada.cpp:3: warning: ada-url@2.2.1: ./deps/ada.h:20:10: fatal error: 'string' file not found warning: ada-url@2.2.1: #include <string> warning: ada-url@2.2.1: ^~~~~~~~ warning: ada-url@2.2.1: 1 error generated. error: failed to run custom build command for `ada-url v2.2.1 (/ada-url)` Caused by: process didn't exit successfully: `/ada-url/target/debug/build/ada-url-ba3156cf87bc7d44/build-script-build` (exit status: 1) --- stdout OPT_LEVEL = Some("0") TARGET = Some("x86_64-unknown-linux-gnu") HOST = Some("x86_64-unknown-linux-gnu") cargo:rerun-if-env-changed=CXX_x86_64-unknown-linux-gnu CXX_x86_64-unknown-linux-gnu = None cargo:rerun-if-env-changed=CXX_x86_64_unknown_linux_gnu CXX_x86_64_unknown_linux_gnu = None cargo:rerun-if-env-changed=HOST_CXX HOST_CXX = None cargo:rerun-if-env-changed=CXX CXX = Some("clang++") cargo:rerun-if-env-changed=CRATE_CC_NO_DEFAULTS CRATE_CC_NO_DEFAULTS = None DEBUG = Some("true") cargo:rerun-if-env-changed=CXXFLAGS_x86_64-unknown-linux-gnu CXXFLAGS_x86_64-unknown-linux-gnu = None cargo:rerun-if-env-changed=CXXFLAGS_x86_64_unknown_linux_gnu CXXFLAGS_x86_64_unknown_linux_gnu = None cargo:rerun-if-env-changed=HOST_CXXFLAGS HOST_CXXFLAGS = None cargo:rerun-if-env-changed=CXXFLAGS CXXFLAGS = None running: "clang++" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-gdwarf-4" "-fno-omit-frame-pointer" "--target=x86_64-unknown-linux-gnu" "-std=c++17" "-I" "./deps/ada.h" "-I" "./deps/ada_c.h" "-Wall" "-Wextra" "-o" "/ada-url/target/debug/build/ada-url-b4939785ec9bcc43/out/./deps/ada.o" "-c" "./deps/ada.cpp" cargo:warning=In file included from ./deps/ada.cpp:3: cargo:warning=./deps/ada.h:20:10: fatal error: 'string' file not found cargo:warning=#include <string> cargo:warning= ^~~~~~~~ cargo:warning=1 error generated. exit status: 1 --- stderr error occurred: Command "clang++" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-gdwarf-4" "-fno-omit-frame-pointer" "--target=x86_64-unknown-linux-gnu" "-std=c++17" "-I" "./deps/ada.h" "-I" "./deps/ada_c.h" "-Wall" "-Wextra" "-o" "/ada-url/target/debug/build/ada-url-b4939785ec9bcc43/out/./deps/ada.o" "-c" "./deps/ada.cpp"with args "clang++" did not execute successfully (status code exit status: 1). ``` </details> It seems that clang cannot find the c++ stdlib... 🤔 Moreover, the build script [unconditionally sets](https://github.com/ada-url/rust/blob/720fa45da6718e483465b7da954a77cff1424d06/build.rs#L178) the compiler to `clang++`, which makes trying another compiler (or another clang version) impossible. If I comment out the [aforementioned line](https://github.com/ada-url/rust/blob/720fa45da6718e483465b7da954a77cff1424d06/build.rs#L179) and build with `CXX=g++ cargo build`, the library builds correctly and tests pass: ```sh $ CXX=g++ cargo build Compiling ada-url v2.2.1 (/ada-url) warning: ada-url@2.2.1: cc1plus: warning: ./deps/ada.h: not a directory warning: ada-url@2.2.1: cc1plus: warning: ./deps/ada_c.h: not a directory Finished dev [unoptimized + debuginfo] target(s) in 3.57s ``` Also note the warnings caused by the build script's passing files to [`cc::Build::include()`](https://docs.rs/cc/latest/cc/struct.Build.html#method.include) instead of directories. IMO, the build script should let the `cc` crate detect the correct compiler on UNIX platforms.