Index: Mk/Uses/cargo.mk
===================================================================
--- Mk/Uses/cargo.mk
+++ Mk/Uses/cargo.mk
@@ -154,6 +154,7 @@
 .if ${CARGO_CRATES:Mlibgit2-sys-[0-9]*}
 # Use the system's libgit2 instead of building the bundled version
 CARGO_ENV+=	LIBGIT2_SYS_USE_PKG_CONFIG=1
+LIB_DEPENDS+=	libgit2.so:devel/libgit2
 .endif
 
 .if ${CARGO_CRATES:Mlibssh2-sys-[0-9]*}
@@ -168,6 +169,14 @@
 # RUSTONIG_SYSTEM_LIBONIG is not necessary, but will force onig_sys to
 # always use the system's libonig as returned by `pkg-config oniguruma`.
 CARGO_ENV+=	RUSTONIG_SYSTEM_LIBONIG=1
+LIB_DEPENDS+=	libonig.so:devel/oniguruma
+.endif
+
+.if ${CARGO_CRATES:Mbindgen-[0-9]*}
+# bindgen leverages libclang to preprocess, parse, and type check C and
+# C++ header files. libclang is not available in base, however is
+# provided with the llvm port
+BUILD_DEPENDS+=	llvm>0:devel/llvm${LLVM_DEFAULT}
 .endif
 
 .if ${CARGO_CRATES:Mopenssl-0.[0-9].*}