diff --git a/lang/rust/src/resolver.sld b/lang/rust/src/resolver.sld
index f2179be..73afe8c 100644
--- a/lang/rust/src/resolver.sld
+++ b/lang/rust/src/resolver.sld
@@ -538,9 +538,14 @@
            (call-runner build-script crate-root
              #~(
                 ("RUSTC" . ,(string-append #$rustc "/bin/rustc"))
+                ("RUSTDOC" . ,(string-append #$rustc "/bin/rustdoc"))
                 ("HOST" . "x86_64-unknown-linux-gnu")
                 ("TARGET" . "x86_64-unknown-linux-gnu")
                 ("OPT_LEVEL" . "0")
+                ("SOURCE_DATE_EPOCH" . "1")
+                ("NUM_JOBS" . "1")
+                ("RUSTFLAGS" . "")
+                ("CARGO_ENCODED_RUSTFLAGS" . "")
                 ("PROFILE" . "debug")
                 ("DEBUG" . "true")
                 ("_zilch_links" . ,(string-join #$(map (lambda (kv) #~,(string-append #$(resolved-package-build-data-build-script-out (cdr kv)) ":" (car kv))) crate-links) "!"))
@@ -548,8 +553,7 @@
                 ,@dependency-metadata
                 ,@rewritten-features
                 ,@(rewrite-env #$build-script-envs)
-                ; TODO: OUT_DIR, NUM_JOBS, OPT_LEVEL/DEBUG/PROFILE
-                ; RUSTC/RUSTDOC?, RUSTC_LINKER? and CARGO_ENCODED_RUSTFLAGS
+                ; TODO: RUSTC_LINKER
                 . #$rustc-env))))
          ; Pass the buildscript-out data to the next crate.
          (set! buildscript-out runner-outpath)