diff --git a/.travis.yml b/.travis.yml
index 7dd5f6efaf07d..a9867cbc11e0e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -46,6 +46,8 @@ matrix:
         RUST_CONFIGURE_ARGS=--build=x86_64-apple-darwin
         SRC=.
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1
+        SCCACHE_ERROR_LOG=/tmp/sccache.log
+        RUST_LOG=sccache
       os: osx
       osx_image: xcode8.2
       install: &osx_install_sccache >
@@ -56,6 +58,8 @@ matrix:
         RUST_CONFIGURE_ARGS=--build=i686-apple-darwin
         SRC=.
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1
+        SCCACHE_ERROR_LOG=/tmp/sccache.log
+        RUST_LOG=sccache
       os: osx
       osx_image: xcode8.2
       install: *osx_install_sccache
@@ -66,6 +70,8 @@ matrix:
         SRC=.
         DEPLOY=1
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1
+        SCCACHE_ERROR_LOG=/tmp/sccache.log
+        RUST_LOG=sccache
       os: osx
       osx_image: xcode8.2
       install: >
@@ -77,6 +83,8 @@ matrix:
         SRC=.
         DEPLOY=1
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1
+        SCCACHE_ERROR_LOG=/tmp/sccache.log
+        RUST_LOG=sccache
       os: osx
       osx_image: xcode8.2
       install: *osx_install_sccache
@@ -92,6 +100,8 @@ matrix:
         SRC=.
         DEPLOY_ALT=1
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1
+        SCCACHE_ERROR_LOG=/tmp/sccache.log
+        RUST_LOG=sccache
       os: osx
       osx_image: xcode8.2
       install: *osx_install_sccache
@@ -133,6 +143,7 @@ after_failure:
       df -h;
       du . | sort -nr | head -n100
   - cat obj/tmp/sccache.log
+  - cat /tmp/sccache.log
 
 # Save tagged docker images we created and load them if they're available
 before_cache:
diff --git a/appveyor.yml b/appveyor.yml
index 9a0a4d81f9b1e..46ff9a252a0f6 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -130,12 +130,19 @@ install:
   - set PATH=%PATH%;%CD%\handle
   - handle.exe -accepteula -help
 
+  # Attempt to debug sccache failures
+  - set RUST_LOG=sccache
+  - set SCCACHE_ERROR_LOG=%CD%/sccache.log
+
 test_script:
   - appveyor-retry sh -c 'git submodule deinit -f . && git submodule update --init'
   - set SRC=.
   - set NO_CCACHE=1
   - sh src/ci/run.sh
 
+on_failure:
+  - cat %CD%/sccache.log
+
 cache:
   - "build/i686-pc-windows-msvc/llvm -> src/rustllvm/llvm-auto-clean-trigger"
   - "build/x86_64-pc-windows-msvc/llvm -> src/rustllvm/llvm-auto-clean-trigger"