diff --git a/developer/src/common/web/utils/build.sh b/developer/src/common/web/utils/build.sh
index ddc66549937..618c9040b31 100755
--- a/developer/src/common/web/utils/build.sh
+++ b/developer/src/common/web/utils/build.sh
@@ -46,18 +46,24 @@ function do_build() {
   tsc --build
 }
 
-builder_run_action clean       rm -rf ./build/
-builder_run_action configure   verify_npm_setup
-builder_run_action build       do_build
+function do_test() {
+  local MOCHA_FLAGS=
+
+  if [[ "${TEAMCITY_GIT_PATH}" != "" ]]; then
+    # we're running in TeamCity
+    MOCHA_FLAGS="-reporter mocha-teamcity-reporter"
+  fi
 
-if builder_start_action test; then
   eslint .
   tsc --build test
   readonly C8_THRESHOLD=50
-  c8 --reporter=lcov --reporter=text --exclude-after-remap --lines $C8_THRESHOLD --statements $C8_THRESHOLD --branches $C8_THRESHOLD --functions $C8_THRESHOLD mocha
+  c8 --reporter=lcov --reporter=text --exclude-after-remap --lines $C8_THRESHOLD --statements $C8_THRESHOLD --branches $C8_THRESHOLD --functions $C8_THRESHOLD mocha ${MOCHA_FLAGS}
   builder_echo warning "Coverage thresholds are currently $C8_THRESHOLD%, which is lower than ideal."
   builder_echo warning "Please increase threshold in build.sh as test coverage improves."
-  builder_finish_action success test
-fi
+}
 
-builder_run_action publish    builder_publish_npm
+builder_run_action clean       rm -rf ./build/
+builder_run_action configure   verify_npm_setup
+builder_run_action build       do_build
+builder_run_action test        do_test
+builder_run_action publish     builder_publish_npm
diff --git a/developer/src/kmc-copy/build.sh b/developer/src/kmc-copy/build.sh
index 023f0c73bf8..7907b6e1814 100755
--- a/developer/src/kmc-copy/build.sh
+++ b/developer/src/kmc-copy/build.sh
@@ -32,12 +32,19 @@ builder_parse "$@"
 do_test() {
   # note: `export TEST_SAVE_ARTIFACTS=1` to save a copy of artifacts to temp path
   # note: `export TEST_SAVE_FIXTURES=1` to get a copy of cloud-based fixtures saved to online/
+  local MOCHA_FLAGS=
+
+  if [[ "${TEAMCITY_GIT_PATH}" != "" ]]; then
+    # we're running in TeamCity
+    MOCHA_FLAGS="-reporter mocha-teamcity-reporter"
+  fi
+
   eslint .
   cd test
   tsc --build
   cd ..
   readonly C8_THRESHOLD=70
-  c8 -skip-full --reporter=lcov --reporter=text --lines $C8_THRESHOLD --statements $C8_THRESHOLD --branches $C8_THRESHOLD --functions $C8_THRESHOLD mocha "${builder_extra_params[@]}"
+  c8 -skip-full --reporter=lcov --reporter=text --lines $C8_THRESHOLD --statements $C8_THRESHOLD --branches $C8_THRESHOLD --functions $C8_THRESHOLD mocha ${MOCHA_FLAGS} "${builder_extra_params[@]}"
   builder_echo warning "Coverage thresholds are currently $C8_THRESHOLD%, which is lower than ideal."
   builder_echo warning "Please increase threshold in build.sh as test coverage improves."
 }
diff --git a/developer/src/kmc-generate/build.sh b/developer/src/kmc-generate/build.sh
index 6a86a9339fe..b52010a0390 100755
--- a/developer/src/kmc-generate/build.sh
+++ b/developer/src/kmc-generate/build.sh
@@ -37,11 +37,18 @@ do_build() {
 }
 
 do_test() {
+  local MOCHA_FLAGS=
+
+  if [[ "${TEAMCITY_GIT_PATH}" != "" ]]; then
+    # we're running in TeamCity
+    MOCHA_FLAGS="-reporter mocha-teamcity-reporter"
+  fi
+
   eslint .
   cd test
   tsc --build
   cd ..
-  c8 --reporter=lcov --reporter=text mocha "${builder_extra_params[@]}"
+  c8 --reporter=lcov --reporter=text mocha ${MOCHA_FLAGS} "${builder_extra_params[@]}"
 }
 
 builder_run_action clean      rm -rf ./build/ ./tsconfig.tsbuildinfo
diff --git a/developer/src/kmc-keyboard-info/build.sh b/developer/src/kmc-keyboard-info/build.sh
index c85d76db015..0f1c7f95d50 100755
--- a/developer/src/kmc-keyboard-info/build.sh
+++ b/developer/src/kmc-keyboard-info/build.sh
@@ -32,23 +32,28 @@ function do_configure() {
   mkdir -p src/imports
   echo 'export default ' > src/imports/langtags.js
   cat "$KEYMAN_ROOT/resources/standards-data/langtags/langtags.json" >> src/imports/langtags.js
+}
+
+function do_test() {
+  local MOCHA_FLAGS=
+
+  if [[ "${TEAMCITY_GIT_PATH}" != "" ]]; then
+    # we're running in TeamCity
+    MOCHA_FLAGS="-reporter mocha-teamcity-reporter"
+  fi
 
+  eslint .
+  tsc --build test
+  c8 --reporter=lcov --reporter=text --exclude-after-remap mocha ${MOCHA_FLAGS}
 }
+
 #-------------------------------------------------------------------------------------------------------------------
 
 builder_run_action clean       rm -rf ./build/ ./tsconfig.tsbuildinfo
 builder_run_action configure   do_configure
 builder_run_action build       tsc --build
 builder_run_action api         api-extractor run --local --verbose
-
-#-------------------------------------------------------------------------------------------------------------------
-
-if builder_start_action test; then
-  eslint .
-  tsc --build test
-  c8 --reporter=lcov --reporter=text --exclude-after-remap mocha
-  builder_finish_action success test
-fi
+builder_run_action test        do_test
 
 #-------------------------------------------------------------------------------------------------------------------
 
diff --git a/developer/src/kmc-kmn/build.sh b/developer/src/kmc-kmn/build.sh
index a0732414758..618e9a4edaf 100755
--- a/developer/src/kmc-kmn/build.sh
+++ b/developer/src/kmc-kmn/build.sh
@@ -56,27 +56,31 @@ function copy_deps() {
   cp ../kmcmplib/build/wasm/$BUILDER_CONFIGURATION/src/wasm-host.wasm ./build/src/import/kmcmplib/wasm-host.wasm
 }
 
-if builder_start_action build; then
+function do_build() {
   copy_deps
   tsc --build
-  builder_finish_action success build
-fi
+}
 
-builder_run_action api        api-extractor run --local --verbose
+function do_test() {
+  local MOCHA_FLAGS=
 
-#-------------------------------------------------------------------------------------------------------------------
+  if [[ "${TEAMCITY_GIT_PATH}" != "" ]]; then
+    # we're running in TeamCity
+    MOCHA_FLAGS="-reporter mocha-teamcity-reporter"
+  fi
 
-if builder_start_action test; then
   copy_deps
   tsc --build test/
   npm run lint
   readonly C8_THRESHOLD=80
-  c8 --reporter=lcov --reporter=text --lines $C8_THRESHOLD --statements $C8_THRESHOLD --branches $C8_THRESHOLD --functions $C8_THRESHOLD mocha
+  c8 --reporter=lcov --reporter=text --lines $C8_THRESHOLD --statements $C8_THRESHOLD --branches $C8_THRESHOLD --functions $C8_THRESHOLD mocha ${MOCHA_FLAGS}
   builder_echo warning "Coverage thresholds are currently $C8_THRESHOLD%, which is lower than ideal."
   builder_echo warning "Please increase threshold in build.sh as test coverage improves."
+}
 
-  builder_finish_action success test
-fi
+builder_run_action build      do_build
+builder_run_action api        api-extractor run --local --verbose
+builder_run_action test       do_test
 
 #-------------------------------------------------------------------------------------------------------------------
 
diff --git a/developer/src/kmc-ldml/build.sh b/developer/src/kmc-ldml/build.sh
index 73a40c79d75..23a2682e353 100755
--- a/developer/src/kmc-ldml/build.sh
+++ b/developer/src/kmc-ldml/build.sh
@@ -33,30 +33,19 @@ builder_describe_outputs \
 
 builder_parse "$@"
 
-#-------------------------------------------------------------------------------------------------------------------
-
-if builder_start_action clean; then
+function do_clean() {
   rm -rf ./build/ ./tsconfig.tsbuildinfo
-  builder_finish_action success clean
-fi
+}
 
-#-------------------------------------------------------------------------------------------------------------------
-
-if builder_start_action configure; then
+function do_configure() {
   verify_npm_setup
-  builder_finish_action success configure
-fi
-
-#-------------------------------------------------------------------------------------------------------------------
+}
 
-if builder_start_action build; then
+function do_build() {
   npm run build
-  builder_finish_action success build
-fi
-
-#-------------------------------------------------------------------------------------------------------------------
+}
 
-if builder_start_action build-fixtures; then
+function do_build_fixtures() {
   # Build basic.kmx and emit its checksum
   mkdir -p ./build/test/fixtures
   node ../kmc build ./test/fixtures/basic.xml --no-compiler-version --debug --out-file ./build/test/fixtures/basic-xml.kmx
@@ -65,22 +54,29 @@ if builder_start_action build-fixtures; then
 
   # Generate a binary file from basic.txt for comparison purposes
   node ../../../common/tools/hextobin/build/hextobin.js ./test/fixtures/basic.txt ./build/test/fixtures/basic-txt.kmx
+}
 
-  builder_finish_action success build-fixtures
-fi
+function do_test() {
+  local MOCHA_FLAGS=
 
-builder_run_action api        api-extractor run --local --verbose
-
-#-------------------------------------------------------------------------------------------------------------------
+  if [[ "${TEAMCITY_GIT_PATH}" != "" ]]; then
+    # we're running in TeamCity
+    MOCHA_FLAGS="-reporter mocha-teamcity-reporter"
+  fi
 
-if builder_start_action test; then
   eslint .
   cd test
   tsc -b
   cd ..
-  c8 --reporter=lcov --reporter=text mocha "${builder_extra_params[@]}"
-  builder_finish_action success test
-fi
+  c8 --reporter=lcov --reporter=text mocha ${MOCHA_FLAGS} "${builder_extra_params[@]}"
+}
+
+builder_run_action clean           do_clean
+builder_run_action configure       do_configure
+builder_run_action build           do_build
+builder_run_action build-fixtures  do_build_fixtures
+builder_run_action api             api-extractor run --local --verbose
+builder_run_action test            do_test
 
 #-------------------------------------------------------------------------------------------------------------------
 
diff --git a/developer/src/kmc-model/build.sh b/developer/src/kmc-model/build.sh
index 372a145312a..9b53402f551 100755
--- a/developer/src/kmc-model/build.sh
+++ b/developer/src/kmc-model/build.sh
@@ -35,10 +35,24 @@ function do_build() {
   npm run build
 }
 
+function do_test() {
+  local MOCHA_FLAGS=
+
+  if [[ "${TEAMCITY_GIT_PATH}" != "" ]]; then
+    # we're running in TeamCity
+    MOCHA_FLAGS="-reporter mocha-teamcity-reporter"
+  fi
+  npm run lint
+  cd test
+  tsc -b
+  cd ..
+  c8 --reporter=lcov --reporter=text mocha ${MOCHA_FLAGS}
+}
+
 builder_run_action clean        rm -rf ./build/ ./tsconfig.tsbuildinfo
 builder_run_action configure    verify_npm_setup
 builder_run_action build        do_build
 builder_run_action api          api-extractor run --local --verbose
-builder_run_action test         npm test
+builder_run_action test         do_test
 builder_run_action publish      builder_publish_npm
 
diff --git a/developer/src/kmc-package/build.sh b/developer/src/kmc-package/build.sh
index 0b2d7bda9b9..c7d5108ff74 100755
--- a/developer/src/kmc-package/build.sh
+++ b/developer/src/kmc-package/build.sh
@@ -30,20 +30,25 @@ builder_describe_outputs \
 
 builder_parse "$@"
 
-#-------------------------------------------------------------------------------------------------------------------
-
-builder_run_action clean      rm -rf ./build/ ./tsconfig.tsbuildinfo
-builder_run_action configure  verify_npm_setup
-builder_run_action build      tsc --build
-builder_run_action api        api-extractor run --local --verbose
+function do_test() {
+  local MOCHA_FLAGS=
 
-if builder_start_action test; then
+  if [[ "${TEAMCITY_GIT_PATH}" != "" ]]; then
+    # we're running in TeamCity
+    MOCHA_FLAGS="-reporter mocha-teamcity-reporter"
+  fi
   eslint .
   cd test
   tsc --build
   cd ..
-  c8 --reporter=lcov --reporter=text mocha
-  builder_finish_action success test
-fi
+  c8 --reporter=lcov --reporter=text mocha ${MOCHA_FLAGS}
+}
 
+#-------------------------------------------------------------------------------------------------------------------
+
+builder_run_action clean      rm -rf ./build/ ./tsconfig.tsbuildinfo
+builder_run_action configure  verify_npm_setup
+builder_run_action build      tsc --build
+builder_run_action api        api-extractor run --local --verbose
+builder_run_action test       do_test
 builder_run_action publish     builder_publish_npm