diff --git a/.bazelrc b/.bazelrc
index c0c7a4f53..3f96f006a 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -1,7 +1,7 @@
 # Must be first. Enables build:windows, build:linux, build:macos, build:freebsd, build:openbsd
 build --enable_platform_specific_config
 ###############################################################################
-# On       Windows, provide: CC=clang, BAZEL_LLVM, BAZEL_SH
+# On       Windows, provide: BAZEL_SH, and BAZEL_LLVM (if using clang-cl)
 # On all platforms, provide: PYTHON3_BIN_PATH=python
 ###############################################################################
 build --action_env=PATH
@@ -17,14 +17,13 @@ build:msvc --compiler=msvc-cl
 #                 for compiling assembly files is fixed on Windows:
 #                 https://github.com/bazelbuild/bazel/issues/8924
 # Warnings should be errors
-build:linux    --per_file_copt="-\\.(asm|S)$,-.*/arrow/util/logging\\.cc@-Werror"
-build:macos    --per_file_copt="-\\.(asm|S)$,-.*/arrow/util/logging\\.cc@-Werror"
-build:clang-cl --per_file_copt="-\\.(asm|S)$,-.*/arrow/util/logging\\.cc@-Werror"
-build:msvc     --per_file_copt="-\\.(asm|S)$,-.*/arrow/util/logging\\.cc@-WX"
+build:linux    --per_file_copt="-\\.(asm|S)$@-Werror"
+build:macos    --per_file_copt="-\\.(asm|S)$@-Werror"
+build:clang-cl --per_file_copt="-\\.(asm|S)$@-Werror"
+build:msvc     --per_file_copt="-\\.(asm|S)$@-WX"
 # Ignore warnings for protobuf generated files and external projects.
 build --per_file_copt="\\.pb\\.cc$@-w"
 build --per_file_copt="-\\.(asm|S)$,external/.*@-w"
-# Enable some C warnings that really should be errors (e.g. implicit void* <-> int conversion)
 # Ignore minor warnings for host tools, which we generally can't control
 build:clang-cl --host_copt="-Wno-inconsistent-missing-override"
 build:clang-cl --host_copt="-Wno-microsoft-unqualified-friend"
@@ -81,6 +80,8 @@ test:asan --test_env=LD_PRELOAD="/usr/lib/x86_64-linux-gnu/libasan.so.2 /usr/lib
 # test:asan --test_env=LD_PRELOAD="/usr/lib/gcc/x86_64-linux-gnu/7/libasan.so"
 
 # CI configuration:
+aquery:ci --color=no
+aquery:ci --noshow_progress
 build:ci --color=yes
 build:ci --curses=no
 build:ci --disk_cache=~/ray-bazel-cache
@@ -98,7 +99,12 @@ test:ci --spawn_strategy=local
 test:ci --test_output=errors
 test:ci --test_verbose_timeout_warnings
 
-# [Linux] Uncomment this line to print a stack trace on exit.
-#test:linux --run_under="bash -c 'if command -v strace >/dev/null && strace -qq -k -e exit true 2>/dev/null; then strace -qq -k -e exit -e trace=\"!all\" -s 32768 -f -o >(awk \"/^[0-9]+ / { y = \\$3 != \\\"SIGCHLD\\\" && \\$3 != \\\"SIGTERM\\\" && \\$5 != \\\"SIGTERM\\\" && \\$5 != \\\"SIGKILL2\\\"; } y { print; }\" 1>&2 && cat 1>&2) -- \"$@\"; else \"$@\"; fi' -"
-# [Linux] Uncomment this line to preload libSegFault.so if available, to print a stack trace on aborts and segfault. (Note: This doesn't always work.)
-#test:linux --run_under="bash -c 'unset GREP_OPTIONS && if ! grep -q -o Microsoft /proc/version 2>/dev/null; then libs=\"$(command -v ldconfig >/dev/null && ldconfig -p | grep -F -o -e \"libSegFault.so\" | uniq | tr \"\\\\n\" :)\" && if [ -n \"${libs%:}\" ]; then export SEGFAULT_SIGNALS=\"abrt segv\" LD_PRELOAD=\"${libs}${LD_PRELOAD-}\"; fi; fi && \"$@\"' -"
+aquery:get-toolchain --include_commandline=false
+aquery:get-toolchain --noimplicit_deps
+
+# [Linux] Uncomment this line (or use --config) to print a stack trace on exit.
+#test:linux --config=strace
+test:strace --run_under="bash -c 'if command -v strace >/dev/null && strace -qq -k -e exit true 2>/dev/null; then strace -qq -k -e exit -e trace=\"!all\" -s 32768 -f -o >(awk \"/^[0-9]+ / { y = \\$3 != \\\"SIGCHLD\\\" && \\$3 != \\\"SIGTERM\\\" && \\$5 != \\\"SIGTERM\\\" && \\$5 != \\\"SIGKILL2\\\"; } y { print; }\" 1>&2 && cat 1>&2) -- \"$@\"; else \"$@\"; fi' -"
+# [Linux] Uncomment this line (or use --config) to preload libSegFault.so if available, to print a stack trace on aborts and segfault. (Note: This doesn't always work.)
+#test:linux --config=segfault
+test:segfault --run_under="bash -c 'unset GREP_OPTIONS && if ! grep -q -o Microsoft /proc/version 2>/dev/null; then libs=\"$(command -v ldconfig >/dev/null && ldconfig -p | grep -F -o -e \"libSegFault.so\" | uniq | tr \"\\\\n\" :)\" && if [ -n \"${libs%:}\" ]; then export SEGFAULT_SIGNALS=\"abrt segv\" LD_PRELOAD=\"${libs}${LD_PRELOAD-}\"; fi; fi && \"$@\"' -"
diff --git a/BUILD.bazel b/BUILD.bazel
index b87f25388..8a209a8ad 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -11,13 +11,13 @@ load("@com_github_google_flatbuffers//:build_defs.bzl", "flatbuffer_cc_library")
 load("//bazel:ray.bzl", "COPTS", "PYX_COPTS", "PYX_SRCS", "copy_to_workspace")
 
 config_setting(
-    name = "windows_msvc-cl",
-    values = {"compiler": "msvc-cl"},
+    name = "msvc-cl",
+    flag_values = {"@bazel_tools//tools/cpp:compiler": "msvc-cl"},
 )
 
 config_setting(
-    name = "windows_clang-cl",
-    values = {"compiler": "clang-cl"},
+    name = "clang-cl",
+    flag_values = {"@bazel_tools//tools/cpp:compiler": "clang-cl"},
 )
 
 # === Begin of protobuf definitions ===
@@ -846,7 +846,7 @@ cc_test(
     name = "reconstruction_policy_test",
     srcs = ["src/ray/raylet/reconstruction_policy_test.cc"],
     copts = COPTS + select({
-        "//:windows_msvc-cl": [
+        "//:msvc-cl": [
         ],
         "//conditions:default": [
             # Ignore this warning since it's impractical to fix in the relevant headers
diff --git a/bazel/BUILD.hiredis b/bazel/BUILD.hiredis
index 7444da799..82c26febb 100644
--- a/bazel/BUILD.hiredis
+++ b/bazel/BUILD.hiredis
@@ -4,6 +4,13 @@ COPTS = [] + select({
     ],
     "//conditions:default": [
     ],
+}) + select({
+    "@//:msvc-cl": [
+    ],
+    "//conditions:default": [
+        # Old versions of GCC (e.g. 4.9.2) can fail to compile Redis's C without this.
+        "-std=c99",
+    ],
 })
 
 # This library is for internal hiredis use, because hiredis assumes a
diff --git a/bazel/ray.bzl b/bazel/ray.bzl
index 5d4abcbc7..1b79e29b9 100644
--- a/bazel/ray.bzl
+++ b/bazel/ray.bzl
@@ -2,24 +2,24 @@ load("@com_github_google_flatbuffers//:build_defs.bzl", "flatbuffer_library_publ
 load("@com_github_checkstyle_java//checkstyle:checkstyle.bzl", "checkstyle_test")
 load("@bazel_common//tools/maven:pom_file.bzl", "pom_file")
 
-WINDOWS_COPTS = [
-    # TODO(mehrdadn): (How to) support dynamic linking?
-    "-DRAY_STATIC",
-]
-
 COPTS = ["-DRAY_USE_GLOG"] + select({
-    "//:windows_msvc-cl": [
-    ] + WINDOWS_COPTS,
-    "//:windows_clang-cl": [
+    "@bazel_tools//src/conditions:windows": [
+        # TODO(mehrdadn): (How to) support dynamic linking?
+        "-DRAY_STATIC",
+    ],
+    "//conditions:default": [
+    ],
+}) + select({
+    "//:clang-cl": [
         "-Wno-builtin-macro-redefined",  # To get rid of warnings caused by deterministic build macros (e.g. #define __DATE__ "redacted")
         "-Wno-microsoft-unqualified-friend",  # This shouldn't normally be enabled, but otherwise we get: google/protobuf/map_field.h: warning: unqualified friend declaration referring to type outside of the nearest enclosing namespace is a Microsoft extension; add a nested name specifier (for: friend class DynamicMessage)
-    ] + WINDOWS_COPTS,
+    ],
     "//conditions:default": [
     ],
 })
 
 PYX_COPTS = select({
-    "//:windows_msvc-cl": [
+    "//:msvc-cl": [
     ],
     "//conditions:default": [
         # Ignore this warning since CPython and Cython have issue removing deprecated tp_print on MacOS
diff --git a/ci/travis/bazel-preclean.sh b/ci/travis/bazel-preclean.sh
index 07a1a014d..cf42a580b 100755
--- a/ci/travis/bazel-preclean.sh
+++ b/ci/travis/bazel-preclean.sh
@@ -13,7 +13,7 @@
 
 (
   set -euo pipefail
-  bazel aquery --color=no --show_progress=no --output=textproto \
+  bazel aquery --output=textproto \
     "mnemonic(\"Genrule\", deps(${1-//:*}))" | awk '
     {
       body = 0;
diff --git a/ci/travis/install-dependencies.sh b/ci/travis/install-dependencies.sh
index 8b0290186..cd85b1703 100755
--- a/ci/travis/install-dependencies.sh
+++ b/ci/travis/install-dependencies.sh
@@ -202,6 +202,7 @@ install_toolchains() {
 install_dependencies() {
 
   install_bazel
+
   install_base
   install_toolchains
   install_nvm
diff --git a/ci/travis/install-toolchains.sh b/ci/travis/install-toolchains.sh
index 87dd6d4de..74857193e 100755
--- a/ci/travis/install-toolchains.sh
+++ b/ci/travis/install-toolchains.sh
@@ -50,4 +50,16 @@ install_clang() {
   "${cc}" --version
 }
 
-install_clang "$@"
+install_toolchains() {
+  local uses_clang=1 some_lightweight_target="//:sha256"
+  if bazel aquery --config=get-toolchain --output=textproto "${some_lightweight_target}" |
+     grep "external_Slocal_Uconfig_Ucc_Cmsvc_Ucompiler_Ufiles" > /dev/null; then
+    # We detected that we use MSVC, not Clang
+    uses_clang=0
+  fi
+  if [ 0 -ne "${uses_clang}" ]; then
+    install_clang "$@"
+  fi
+}
+
+install_toolchains "$@"