diff --git a/Cargo.lock b/Cargo.lock
index f586e9facc6..b47e8147404 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3678,7 +3678,6 @@ dependencies = [
  "libloading",
  "measureme 10.0.0",
  "rustc-demangle",
- "rustc_arena",
  "rustc_ast",
  "rustc_attr",
  "rustc_codegen_ssa",
@@ -3801,7 +3800,6 @@ dependencies = [
  "rustc_ast",
  "rustc_ast_pretty",
  "rustc_codegen_ssa",
- "rustc_const_eval",
  "rustc_data_structures",
  "rustc_error_codes",
  "rustc_errors",
@@ -3816,7 +3814,6 @@ dependencies = [
  "rustc_parse",
  "rustc_plugin_impl",
  "rustc_save_analysis",
- "rustc_serialize",
  "rustc_session",
  "rustc_span",
  "rustc_target",
@@ -3912,7 +3909,6 @@ dependencies = [
  "rustc_ast",
  "rustc_data_structures",
  "rustc_error_messages",
- "rustc_feature",
  "rustc_index",
  "rustc_macros",
  "rustc_serialize",
@@ -3973,7 +3969,6 @@ dependencies = [
  "rustc_macros",
  "rustc_middle",
  "rustc_serialize",
- "rustc_session",
  "rustc_span",
  "rustc_target",
  "smallvec",
@@ -4207,7 +4202,6 @@ dependencies = [
  "rustc_index",
  "rustc_middle",
  "rustc_serialize",
- "rustc_session",
  "rustc_span",
  "rustc_target",
  "smallvec",
@@ -4229,7 +4223,6 @@ dependencies = [
  "rustc_index",
  "rustc_middle",
  "rustc_mir_dataflow",
- "rustc_query_system",
  "rustc_serialize",
  "rustc_session",
  "rustc_span",
@@ -4244,7 +4237,6 @@ name = "rustc_monomorphize"
 version = "0.0.0"
 dependencies = [
  "rustc_data_structures",
- "rustc_errors",
  "rustc_hir",
  "rustc_index",
  "rustc_middle",
@@ -4296,7 +4288,6 @@ dependencies = [
  "rustc_index",
  "rustc_lexer",
  "rustc_middle",
- "rustc_parse",
  "rustc_serialize",
  "rustc_session",
  "rustc_span",
@@ -4311,10 +4302,8 @@ dependencies = [
  "libloading",
  "rustc_ast",
  "rustc_errors",
- "rustc_hir",
  "rustc_lint",
  "rustc_metadata",
- "rustc_middle",
  "rustc_session",
  "rustc_span",
 ]
@@ -4353,7 +4342,6 @@ dependencies = [
  "rustc_serialize",
  "rustc_session",
  "rustc_span",
- "rustc_type_ir",
  "tracing",
 ]
 
@@ -4375,7 +4363,6 @@ dependencies = [
  "rustc_session",
  "rustc_span",
  "rustc_target",
- "rustc_type_ir",
  "smallvec",
  "tracing",
 ]
@@ -4495,7 +4482,6 @@ dependencies = [
  "rustc_data_structures",
  "rustc_hir",
  "rustc_middle",
- "rustc_query_system",
  "rustc_session",
  "rustc_span",
  "rustc_target",
diff --git a/compiler/rustc_codegen_llvm/Cargo.toml b/compiler/rustc_codegen_llvm/Cargo.toml
index 9bded25c09e..b486af13376 100644
--- a/compiler/rustc_codegen_llvm/Cargo.toml
+++ b/compiler/rustc_codegen_llvm/Cargo.toml
@@ -16,7 +16,6 @@ measureme = "10.0.0"
 tracing = "0.1"
 rustc_middle = { path = "../rustc_middle" }
 rustc-demangle = "0.1.21"
-rustc_arena = { path = "../rustc_arena" }
 rustc_attr = { path = "../rustc_attr" }
 rustc_codegen_ssa = { path = "../rustc_codegen_ssa" }
 rustc_symbol_mangling = { path = "../rustc_symbol_mangling" }
diff --git a/compiler/rustc_driver/Cargo.toml b/compiler/rustc_driver/Cargo.toml
index a2cbd9abc90..08d5d4f343c 100644
--- a/compiler/rustc_driver/Cargo.toml
+++ b/compiler/rustc_driver/Cargo.toml
@@ -7,7 +7,6 @@ edition = "2021"
 crate-type = ["dylib"]
 
 [dependencies]
-libc = "0.2"
 tracing = { version = "0.1.28" }
 serde_json = "1.0.59"
 rustc_log = { path = "../rustc_log" }
@@ -21,7 +20,6 @@ rustc_feature = { path = "../rustc_feature" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_hir_pretty = { path = "../rustc_hir_pretty" }
 rustc_metadata = { path = "../rustc_metadata" }
-rustc_const_eval = { path = "../rustc_const_eval" }
 rustc_parse = { path = "../rustc_parse" }
 rustc_plugin_impl = { path = "../rustc_plugin_impl" }
 rustc_save_analysis = { path = "../rustc_save_analysis" }
@@ -29,11 +27,13 @@ rustc_codegen_ssa = { path = "../rustc_codegen_ssa" }
 rustc_session = { path = "../rustc_session" }
 rustc_error_codes = { path = "../rustc_error_codes" }
 rustc_interface = { path = "../rustc_interface" }
-rustc_serialize = { path = "../rustc_serialize" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_span = { path = "../rustc_span" }
 rustc_typeck = { path = "../rustc_typeck" }
 
+[target.'cfg(unix)'.dependencies]
+libc = "0.2"
+
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3", features = ["consoleapi", "debugapi", "processenv"] }
 
diff --git a/compiler/rustc_hir/Cargo.toml b/compiler/rustc_hir/Cargo.toml
index 34d366f4013..47ace7ca3a7 100644
--- a/compiler/rustc_hir/Cargo.toml
+++ b/compiler/rustc_hir/Cargo.toml
@@ -8,7 +8,6 @@ doctest = false
 
 [dependencies]
 rustc_target = { path = "../rustc_target" }
-rustc_feature = { path = "../rustc_feature" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_error_messages = { path = "../rustc_error_messages" }
diff --git a/compiler/rustc_infer/Cargo.toml b/compiler/rustc_infer/Cargo.toml
index f87ea43b1a7..bbc2b767734 100644
--- a/compiler/rustc_infer/Cargo.toml
+++ b/compiler/rustc_infer/Cargo.toml
@@ -14,7 +14,6 @@ rustc_errors = { path = "../rustc_errors" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
-rustc_session = { path = "../rustc_session" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
diff --git a/compiler/rustc_interface/Cargo.toml b/compiler/rustc_interface/Cargo.toml
index 47dc5f2ef86..26b1b9948a0 100644
--- a/compiler/rustc_interface/Cargo.toml
+++ b/compiler/rustc_interface/Cargo.toml
@@ -7,7 +7,6 @@ edition = "2021"
 doctest = false
 
 [dependencies]
-libc = "0.2"
 libloading = "0.7.1"
 tracing = "0.1"
 rustc-rayon-core = { version = "0.4.0", optional = true }
@@ -49,6 +48,9 @@ rustc_trait_selection = { path = "../rustc_trait_selection" }
 rustc_ty_utils = { path = "../rustc_ty_utils" }
 tempfile = "3.2"
 
+[target.'cfg(unix)'.dependencies]
+libc = "0.2"
+
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3", features = ["libloaderapi"] }
 
diff --git a/compiler/rustc_mir_dataflow/Cargo.toml b/compiler/rustc_mir_dataflow/Cargo.toml
index ffd7e3cd06b..a0c70a3fd81 100644
--- a/compiler/rustc_mir_dataflow/Cargo.toml
+++ b/compiler/rustc_mir_dataflow/Cargo.toml
@@ -18,6 +18,5 @@ rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_serialize = { path = "../rustc_serialize" }
-rustc_session = { path = "../rustc_session" }
 rustc_target = { path = "../rustc_target" }
 rustc_span = { path = "../rustc_span" }
diff --git a/compiler/rustc_mir_transform/Cargo.toml b/compiler/rustc_mir_transform/Cargo.toml
index 4c1a7eaf6f0..8a8098e9ab9 100644
--- a/compiler/rustc_mir_transform/Cargo.toml
+++ b/compiler/rustc_mir_transform/Cargo.toml
@@ -19,7 +19,6 @@ rustc_index = { path = "../rustc_index" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_const_eval = { path = "../rustc_const_eval" }
 rustc_mir_dataflow = { path = "../rustc_mir_dataflow" }
-rustc_query_system = { path = "../rustc_query_system" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_session = { path = "../rustc_session" }
 rustc_target = { path = "../rustc_target" }
diff --git a/compiler/rustc_monomorphize/Cargo.toml b/compiler/rustc_monomorphize/Cargo.toml
index f812afe6b62..e4ac47f4982 100644
--- a/compiler/rustc_monomorphize/Cargo.toml
+++ b/compiler/rustc_monomorphize/Cargo.toml
@@ -10,7 +10,6 @@ doctest = false
 smallvec = { version = "1.6.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 rustc_data_structures = { path = "../rustc_data_structures" }
-rustc_errors = { path = "../rustc_errors" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_middle = { path = "../rustc_middle" }
diff --git a/compiler/rustc_passes/Cargo.toml b/compiler/rustc_passes/Cargo.toml
index a3ef1981e84..787d37277c6 100644
--- a/compiler/rustc_passes/Cargo.toml
+++ b/compiler/rustc_passes/Cargo.toml
@@ -12,7 +12,6 @@ rustc_errors = { path = "../rustc_errors" }
 rustc_expand = { path = "../rustc_expand" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
-rustc_parse = { path = "../rustc_parse" }
 rustc_session = { path = "../rustc_session" }
 rustc_target = { path = "../rustc_target" }
 rustc_ast = { path = "../rustc_ast" }
diff --git a/compiler/rustc_plugin_impl/Cargo.toml b/compiler/rustc_plugin_impl/Cargo.toml
index f5071eb6e8f..b6ea533c80b 100644
--- a/compiler/rustc_plugin_impl/Cargo.toml
+++ b/compiler/rustc_plugin_impl/Cargo.toml
@@ -9,9 +9,7 @@ doctest = false
 
 [dependencies]
 libloading = "0.7.1"
-rustc_middle = { path = "../rustc_middle" }
 rustc_errors = { path = "../rustc_errors" }
-rustc_hir = { path = "../rustc_hir" }
 rustc_lint = { path = "../rustc_lint" }
 rustc_metadata = { path = "../rustc_metadata" }
 rustc_ast = { path = "../rustc_ast" }
diff --git a/compiler/rustc_query_impl/Cargo.toml b/compiler/rustc_query_impl/Cargo.toml
index 856f09b6fcc..5673bb83b15 100644
--- a/compiler/rustc_query_impl/Cargo.toml
+++ b/compiler/rustc_query_impl/Cargo.toml
@@ -20,7 +20,6 @@ rustc_query_system = { path = "../rustc_query_system" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
-rustc_type_ir = { path = "../rustc_type_ir" }
 tracing = "0.1"
 
 [features]
diff --git a/compiler/rustc_query_system/Cargo.toml b/compiler/rustc_query_system/Cargo.toml
index 85fbb08eeeb..b5a37cf324b 100644
--- a/compiler/rustc_query_system/Cargo.toml
+++ b/compiler/rustc_query_system/Cargo.toml
@@ -21,7 +21,6 @@ rustc_serialize = { path = "../rustc_serialize" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
-rustc_type_ir = { path = "../rustc_type_ir" }
 parking_lot = "0.11"
 smallvec = { version = "1.6.1", features = ["union", "may_dangle"] }
 
diff --git a/compiler/rustc_symbol_mangling/Cargo.toml b/compiler/rustc_symbol_mangling/Cargo.toml
index b9751f0adb5..d5befa10e23 100644
--- a/compiler/rustc_symbol_mangling/Cargo.toml
+++ b/compiler/rustc_symbol_mangling/Cargo.toml
@@ -16,5 +16,4 @@ rustc_middle = { path = "../rustc_middle" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_target = { path = "../rustc_target" }
 rustc_data_structures = { path = "../rustc_data_structures" }
-rustc_query_system = { path = "../rustc_query_system" }
 rustc_session = { path = "../rustc_session" }