diff --git a/.travis.yml b/.travis.yml
index 390390317d..e1ced372fb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,19 +13,21 @@ env:
     - JOBS=1 # See https://git.io/vdao3 for details.
     - DATABASE_URL=postgres://postgres:@localhost/cargo_registry_test
     - TEST_DATABASE_URL=postgres://postgres:@localhost/cargo_registry_test
-    - CARGO_TARGET_DIR=target
+    - CARGO_INCREMENTAL=0
     - PERCY_PARALLEL_TOTAL=2
     # Percy secrets are included here to enable Percy's GitHub integration
     # on community-submitted PRs
     - PERCY_TOKEN=0d8707a02b19aebbec79bb0bf302b8d2fa95edb33169cfe41b084289596670b1
     - PERCY_PROJECT=crates-io/crates.io
     - PGPORT=5433
+    - PATH=$HOME/.cargo/bin:$PATH
+    - RUSTFLAGS="-C debuginfo=0"
 
 install:
   - sudo cp /etc/postgresql/10/main/pg_hba.conf /etc/postgresql/11/main/pg_hba.conf
   - sudo systemctl restart postgresql@11-main
   - script/ci/cargo-clean-on-new-rustc-version.sh
-  - cargo install --force diesel_cli --vers `cat .diesel_version` --no-default-features --features postgres && export PATH=$HOME/.cargo/bin:$PATH
+  - which diesel || cargo install diesel_cli --vers `cat .diesel_version` --no-default-features --features postgres
 
 before_script:
   - diesel database setup --locked-schema
diff --git a/script/ci/cargo-clean-on-new-rustc-version.sh b/script/ci/cargo-clean-on-new-rustc-version.sh
index 8cbda26267..af510fdf26 100755
--- a/script/ci/cargo-clean-on-new-rustc-version.sh
+++ b/script/ci/cargo-clean-on-new-rustc-version.sh
@@ -3,7 +3,7 @@
 set -e
 
 manual_stamp_file=target/ci_manual_stamp
-manual_stamp=7 # Change this to force a clean build on CI
+manual_stamp=8 # Change this to force a clean build on CI
 
 if [ -f $manual_stamp_file ]; then
     if echo "$manual_stamp" | cmp -s $manual_stamp_file -; then
diff --git a/script/ci/prune-cache.sh b/script/ci/prune-cache.sh
index 6e04ef7010..79a349e91f 100755
--- a/script/ci/prune-cache.sh
+++ b/script/ci/prune-cache.sh
@@ -25,5 +25,7 @@ for name in $bin_names; do
     rm -v target/debug/deps/$normalized-*
 done
 
+rm -v target/.rustc_info.json
+
 echo "Final cache size:"
 du -hs target/debug