diff --git a/appveyor.yml b/appveyor.yml
index a5e70156ba87..7971f3c713be 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -59,6 +59,9 @@ install:
 #  - ps: $blockRdp = $true; iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1'))
 
 build_script:
+  - set CARGO_HOME=C:\Users\appveyor\.cargo
+  - mach clean-nightlies --keep 2 --force
+  - mach clean-cargo-cache --keep 2 --force
   - mach build -d -v
   - mach test-unit
 
diff --git a/etc/ci/buildbot_steps.yml b/etc/ci/buildbot_steps.yml
index 13bab95c46da..041beec8b051 100644
--- a/etc/ci/buildbot_steps.yml
+++ b/etc/ci/buildbot_steps.yml
@@ -4,6 +4,7 @@ env:
 
 mac-rel-wpt1:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env PKG_CONFIG_PATH=/usr/local/opt/zlib/lib/pkgconfig ./mach build --release
   - ./mach run -r -o output.png
   - ./mach test-wpt-failure
@@ -15,6 +16,7 @@ mac-rel-wpt1:
 
 mac-rel-wpt2:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env PKG_CONFIG_PATH=/usr/local/opt/zlib/lib/pkgconfig ./mach build --release
   - ./mach test-wpt --release --processes 4 --total-chunks 6 --this-chunk 2 --log-raw test-wpt.log --log-errorsummary wpt-errorsummary.log --always-succeed
   - ./mach filter-intermittents wpt-errorsummary.log --log-intermittents intermittents.log --log-filteredsummary filtered-wpt-errorsummary.log --tracker-api default --reporter-api default
@@ -22,12 +24,14 @@ mac-rel-wpt2:
 
 mac-rel-wpt3:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env PKG_CONFIG_PATH=/usr/local/opt/zlib/lib/pkgconfig ./mach build --release
   - ./mach test-wpt --release --processes 4 --total-chunks 6 --this-chunk 3 --log-raw test-wpt.log --log-errorsummary wpt-errorsummary.log --always-succeed
   - ./mach filter-intermittents wpt-errorsummary.log --log-intermittents intermittents.log --log-filteredsummary filtered-wpt-errorsummary.log --tracker-api default --reporter-api default
 
 mac-rel-wpt4:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env PKG_CONFIG_PATH=/usr/local/opt/zlib/lib/pkgconfig ./mach build --release
   - ./mach test-wpt --release --processes 4 --total-chunks 6 --this-chunk 4 --log-raw test-wpt.log --log-errorsummary wpt-errorsummary.log --always-succeed
   - ./mach filter-intermittents wpt-errorsummary.log --log-intermittents intermittents.log --log-filteredsummary filtered-wpt-errorsummary.log --tracker-api default --reporter-api default
@@ -36,6 +40,7 @@ mac-rel-wpt4:
 
 mac-dev-unit:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env PKG_CONFIG_PATH=/usr/local/opt/zlib/lib/pkgconfig ./mach build --dev
   - env PKG_CONFIG_PATH=/usr/local/opt/zlib/lib/pkgconfig ./mach test-unit
   - ./mach package --dev
@@ -46,6 +51,7 @@ mac-dev-unit:
 
 mac-rel-css1:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env PKG_CONFIG_PATH=/usr/local/opt/zlib/lib/pkgconfig ./mach build --release
   - ./mach test-wpt --release --processes 4 --total-chunks 6 --this-chunk 5 --log-raw test-wpt.log --log-errorsummary wpt-errorsummary.log --always-succeed
   - ./mach filter-intermittents wpt-errorsummary.log --log-intermittents intermittents.log --log-filteredsummary filtered-wpt-errorsummary.log --tracker-api default --reporter-api default
@@ -54,34 +60,40 @@ mac-rel-css1:
 
 mac-rel-css2:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env PKG_CONFIG_PATH=/usr/local/opt/zlib/lib/pkgconfig ./mach build --release
   - ./mach test-wpt --release --processes 4 --total-chunks 6 --this-chunk 6 --log-raw test-wpt.log --log-errorsummary wpt-errorsummary.log --always-succeed
   - ./mach filter-intermittents wpt-errorsummary.log --log-intermittents intermittents.log --log-filteredsummary filtered-wpt-errorsummary.log --tracker-api default --reporter-api default
 
 mac-nightly:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env PKG_CONFIG_PATH=/usr/local/opt/zlib/lib/pkgconfig ./mach build --release
   - ./mach package --release
   - ./mach upload-nightly mac
 
 linux-rel-intermittent:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env CC=gcc-5 CXX=g++-5 ./mach build --release
   - ./etc/ci/check_intermittents.sh --log-raw intermittents.log
 
 linux-rel-nogate:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env CC=gcc-5 CXX=g++-5 ./mach build --release
   - python ./etc/ci/chaos_monkey_test.py
   - env CC=gcc-5 CXX=g++-5 RUSTFLAGS= bash ./etc/ci/mutation_test.sh
 
 mac-rel-intermittent:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env PKG_CONFIG_PATH=/usr/local/opt/zlib/lib/pkgconfig ./mach build --release
   - ./etc/ci/check_intermittents.sh --log-raw intermittents.log
 
 linux-dev:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - ./mach test-tidy --no-progress --all
   - ./mach test-tidy --no-progress --self-test
   - env CC=gcc-5 CXX=g++-5 ./mach build --dev
@@ -97,6 +109,7 @@ linux-dev:
 
 linux-rel-wpt:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env CC=gcc-5 CXX=g++-5 ./mach build --release --with-debug-assertions
   - ./mach test-wpt-failure
   - ./mach test-wpt --release --processes 24 --total-chunks 2 --this-chunk 1 --log-raw test-wpt.log --log-errorsummary wpt-errorsummary.log --always-succeed
@@ -105,6 +118,7 @@ linux-rel-wpt:
 
 linux-rel-css:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env CC=gcc-5 CXX=g++-5 ./mach build --release --with-debug-assertions
   - ./mach test-wpt --release --processes 24 --total-chunks 2 --this-chunk 2 --log-raw test-wpt.log --log-errorsummary wpt-errorsummary.log --always-succeed
   - ./mach filter-intermittents wpt-errorsummary.log --log-intermittents intermittents.log --log-filteredsummary filtered-wpt-errorsummary.log --tracker-api default --reporter-api default
@@ -115,6 +129,7 @@ linux-rel-css:
 
 linux-nightly:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env CC=gcc-5 CXX=g++-5 ./mach build --release
   - ./mach package --release
   - ./mach upload-nightly linux
@@ -124,6 +139,7 @@ linux-nightly:
 
 android:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env ANDROID_SDK=/home/servo/android/sdk/r25.2.3 ./mach build --android --dev
   - env ANDROID_SDK=/home/servo/android/sdk/r25.2.3 ./mach package --android --dev
   - bash ./etc/ci/lockfile_changed.sh
@@ -132,23 +148,27 @@ android:
 
 android-nightly:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - env ANDROID_SDK=/home/servo/android/sdk/r25.2.3 ./mach build --android --release
   - env ANDROID_SDK=/home/servo/android/sdk/r25.2.3 ./mach package --android --release
   - ./mach upload-nightly android
 
 arm32:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - ./mach build --rel --target=arm-unknown-linux-gnueabihf
   - bash ./etc/ci/lockfile_changed.sh
   - bash ./etc/ci/manifest_changed.sh
 
 arm64:
   - ./mach clean-nightlies --keep 3 --force
+  - ./mach clean-cargo-cache --keep 3 --force
   - ./mach build --rel --target=aarch64-unknown-linux-gnu
   - bash ./etc/ci/lockfile_changed.sh
   - bash ./etc/ci/manifest_changed.sh
 
 windows-msvc-dev:
+  - mach.bat clean-cargo-cache --keep 3 --force
   - mach.bat clean-nightlies --keep 3 --force
   - mach.bat build --dev
   - mach.bat test-unit
@@ -157,6 +177,7 @@ windows-msvc-dev:
   - mach.bat test-stylo
 
 windows-msvc-nightly:
+  - mach.bat clean-cargo-cache --keep 3 --force
   - mach.bat clean-nightlies --keep 3 --force
   - mach.bat build --release
   - mach.bat package --release
diff --git a/python/servo/bootstrap_commands.py b/python/servo/bootstrap_commands.py
index ccc971e5b570..903917856981 100644
--- a/python/servo/bootstrap_commands.py
+++ b/python/servo/bootstrap_commands.py
@@ -169,10 +169,7 @@ def clean_nightlies(self, force=False, keep=None):
     @CommandArgument('--keep',
                      default='1',
                      help='Keep up to this many most recent dependencies')
-    @CommandArgument('--custom-path', '-c',
-                     action='store_true',
-                     help='Get Cargo path from CARGO_HOME environment variable')
-    def clean_cargo_cache(self, force=False, show_size=False, keep=None, custom_path=False):
+    def clean_cargo_cache(self, force=False, show_size=False, keep=None):
         def get_size(path):
             if os.path.isfile(path):
                 return os.path.getsize(path) / (1024 * 1024.0)
@@ -189,7 +186,7 @@ def get_size(path):
             'git': {},
         }
         import toml
-        if os.environ.get("CARGO_HOME", "") and custom_path:
+        if os.environ.get("CARGO_HOME", ""):
             cargo_dir = os.environ.get("CARGO_HOME")
         else:
             cargo_dir = path.join(self.context.topdir, ".cargo")
@@ -317,7 +314,10 @@ def get_size(path):
                                 print("Removing `{}`{} package from {}".format(*print_msg))
                                 for crate_path in crate_paths:
                                     if os.path.exists(crate_path):
-                                        delete(crate_path)
+                                        try:
+                                            delete(crate_path)
+                                        except:
+                                            print("Delete %s failed!" % crate_path)
                             else:
                                 print("Would remove `{}`{} package from {}".format(*print_msg))