diff --git a/CHANGELOG.md b/CHANGELOG.md
index fc2fa7a4..11958d3d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,9 @@
 ## Unreleased
 
 ### Fixed
+- `--stop-on-failure`, `--log-junit`, `--report-html`, `--report-tap` and `--report-json` no longer leak into nested bashunit runs via the environment: a script under test that itself calls bashunit used to inherit the parent's stop-on-failure mode (aborting before the rerun cache was written) and overwrite the parent's report files (#834)
+- `./bashunit bench` works again when running from a repository checkout: the dev entrypoint never sourced `src/benchmark.sh`, so every bench run crashed with `command not found` (the built binary was unaffected) (#834)
+- `./build.sh --verify` now exits non-zero when the built binary fails the test suite — previously a red verification run still reported success to CI. The gate exposed that verification had been silently crashing mid-suite since 2025-06: six test files resolved repo paths through the running binary's root dir, which has no `src/` in a build folder; they now resolve paths relative to the test file or repo cwd (#834)
 - Snapshot placeholders (`::ignore::`) now work on systems without perl; multi-line placeholders still need perl (#823)
 - Runs no longer leak a scratch directory under `$TMPDIR/bashunit/run/` — it is removed on exit, including `--version`/`--help`, subcommands and Ctrl-C (#811)
 - `bashunit::helper::get_function_line_number` no longer disables `extdebug` for its caller (#808)
@@ -16,6 +19,7 @@
 - `--jobs auto` / `-j auto` caps parallel concurrency at the CPU core count (portable across Linux/macOS/BSD); the default stays unlimited (#766)
 
 ### Changed
+- `build.sh` hardened: runs under `set -euo pipefail`, derives the embed list from the entrypoint's `source` order (single source of truth), guards against duplicate embeds and missing doc markers, drops `eval`, and gates every build behind `bash -n` (#834)
 - `bashunit doc` no longer forks an `echo | sed` pipe per line of the assertion docs: a single awk pass prints the same bytes in ~50ms instead of ~5s (#832)
 - Multi-file runs are no longer quadratic in file count: each file's test functions are unset once the file has been processed, so test subshells stop forking an ever-growing shell. bashunit's own 63-file unit suite: ~64s -> ~22s sequential, ~26s -> ~7s parallel (#829)
 - Major performance work with no behaviour change: assertions, per-test execution, per-file discovery, cold start and parallel result publishing are now (near) fork-free, snapshots and `--tag` scans are cached, and quadratic failure rendering is single-pass. Benchmarks on bash 3.2: 100x10 `assert_equals` ~1.50s -> ~0.76s, 500 snapshot assertions ~7.5s -> ~3.0s, 100 tagged tests ~2.92s -> ~0.68s, and bashunit's own acceptance suite ~61s -> ~17s (#761-#764, #772-#775, #798, #801-#807, #809, #810, #813, #817)
diff --git a/bashunit b/bashunit
index 0b00c177..08763508 100755
--- a/bashunit
+++ b/bashunit
@@ -78,6 +78,7 @@ source "$BASHUNIT_ROOT_DIR/src/doc.sh"
 source "$BASHUNIT_ROOT_DIR/src/reports.sh"
 source "$BASHUNIT_ROOT_DIR/src/rerun.sh"
 source "$BASHUNIT_ROOT_DIR/src/runner.sh"
+source "$BASHUNIT_ROOT_DIR/src/benchmark.sh"
 source "$BASHUNIT_ROOT_DIR/src/bashunit.sh"
 source "$BASHUNIT_ROOT_DIR/src/init.sh"
 source "$BASHUNIT_ROOT_DIR/src/learn.sh"
diff --git a/build.sh b/build.sh
index 296f7eb5..0b317bb2 100755
--- a/build.sh
+++ b/build.sh
@@ -1,10 +1,17 @@
 #!/usr/bin/env bash
+set -euo pipefail
 
 source src/check_os.sh
+bashunit::check_os::init
 
 BASHUNIT_ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 export BASHUNIT_ROOT_DIR
 
+# Files already embedded by build::process_file. The source graph is a tree
+# today, but one added cross-source would otherwise silently bundle a file
+# twice (duplicate function definitions and double top-level execution).
+_BUILD_EMBEDDED_FILES=""
+
 function build() {
   local out=$1
 
@@ -21,38 +28,41 @@ function build::verify() {
 
   echo "Verifying build ⏱️"
 
-  BASHUNIT_BUILD_DIR="$out_dir" "$out" tests \
+  if ! BASHUNIT_BUILD_DIR="$out_dir" "$out" tests \
     --simple \
     --parallel \
     --log-junit "$out_dir/log-junit.xml" \
     --report-html "$out_dir/report.html" \
-    --stop-on-failure
-
-  # shellcheck disable=SC2181
-  if [[ $? -eq 0 ]]; then
-    echo "✅ Build verified ✅"
+    --stop-on-failure; then
+    echo "❌ Build verification failed" >&2
+    exit 1
   fi
+
+  echo "✅ Build verified ✅"
 }
 
 function build::generate_bin() {
   local out=$1
   local temp
-  temp="$(dirname "$out")/temp.sh"
+  temp="$(dirname "$out")/temp.$$.sh"
 
   echo '#!/usr/bin/env bash' >"$temp"
   echo "Generating bashunit in the '$(dirname "$out")' folder..."
 
+  local file
   for file in $(build::dependencies); do
     build::process_file "$file" "$temp"
   done
 
   cat bashunit >>"$temp"
-  grep -v '^source' "$temp" >"$out"
+  grep -v '^source ' "$temp" >"$out"
   rm "$temp"
   chmod u+x "$out"
 
   # Embed the assertions.md docs into the binary
   build::embed_docs "$out"
+
+  build::assert_valid_syntax "$out"
 }
 
 # Recursive function to process each file and any files it sources
@@ -60,20 +70,26 @@ function build::process_file() {
   local file=$1
   local temp=$2
 
+  case " $_BUILD_EMBEDDED_FILES " in
+  *" $file "*) return ;;
+  esac
+  _BUILD_EMBEDDED_FILES="$_BUILD_EMBEDDED_FILES $file"
+
   {
     echo "# $(basename "$file")"
-    tail -n +2 "$file" >>"$temp"
+    tail -n +2 "$file"
     echo ""
   } >>"$temp"
 
-  # Search for any 'source' lines in the current file
-  grep '^source ' "$file" | while read -r line; do
-    # Extract the path from the 'source' command
+  # Recurse into any 'source' lines of the current file. Process substitution
+  # (not a pipe) keeps the loop in this shell so _BUILD_EMBEDDED_FILES persists.
+  local line
+  while read -r line; do
     local sourced_file
     sourced_file=$(echo "$line" | awk '{print $2}' | sed 's/^"//;s/"$//') # Remove any quotes
 
-    # Handle cases where the path uses $BASHUNIT_ROOT_DIR or other variables
-    sourced_file=$(eval echo "$sourced_file")
+    # Expand the literal $BASHUNIT_ROOT_DIR prefix without eval
+    sourced_file="${sourced_file/\$BASHUNIT_ROOT_DIR/$BASHUNIT_ROOT_DIR}"
 
     # Handle relative paths if necessary
     local _absolute_path_pattern='^/'
@@ -85,42 +101,16 @@ function build::process_file() {
     if [[ -f "$sourced_file" ]]; then
       build::process_file "$sourced_file" "$temp"
     fi
-  done
+  done < <(grep '^source ' "$file" || true)
 }
 
+# The embed list is derived from the entrypoint's own source order: a single
+# source of truth, so a src file added to the entrypoint can never be missing
+# from the distributable (regressions: bench #0.31.0, watch #735).
 function build::dependencies() {
-  deps=(
-    "src/check_os.sh"
-    "src/str.sh"
-    "src/globals.sh"
-    "src/dependencies.sh"
-    "src/io.sh"
-    "src/math.sh"
-    "src/parallel.sh"
-    "src/env.sh"
-    "src/coverage.sh"
-    "src/clock.sh"
-    "src/state.sh"
-    "src/colors.sh"
-    "src/console_header.sh"
-    "src/console_results.sh"
-    "src/helpers.sh"
-    "src/test_title.sh"
-    "src/upgrade.sh"
-    "src/watch.sh"
-    "src/assertions.sh"
-    "src/reports.sh"
-    "src/rerun.sh"
-    "src/runner.sh"
-    "src/benchmark.sh"
-    "src/init.sh"
-    "src/learn.sh"
-    "src/doc.sh"
-    "src/bashunit.sh"
-    "src/main.sh"
-  )
-
-  echo "${deps[@]}"
+  grep '^source ' bashunit \
+    | sed -e 's|^source "\$BASHUNIT_ROOT_DIR/||' -e 's|"$||' \
+    | grep -v '^src/dev/'
 }
 
 function build::embed_docs() {
@@ -128,12 +118,21 @@ function build::embed_docs() {
   local docs_file="docs/assertions.md"
   local temp_file="${file}.tmp"
 
+  local start_line
+  start_line=$(grep -n "# __BASHUNIT_EMBEDDED_DOCS_START__" "$file" | cut -d: -f1 | head -n 1) || true
+  if [[ -z "$start_line" ]]; then
+    echo "❌ Embed marker __BASHUNIT_EMBEDDED_DOCS_START__ not found in $file" >&2
+    exit 1
+  fi
+  if ! grep -q "# __BASHUNIT_EMBEDDED_DOCS_END__" "$file"; then
+    echo "❌ Embed marker __BASHUNIT_EMBEDDED_DOCS_END__ not found in $file" >&2
+    exit 1
+  fi
+
   # Build the replacement content
   {
     # Print everything before the start marker (excluding the marker line)
-    local line_num
-    line_num=$(grep -n "# __BASHUNIT_EMBEDDED_DOCS_START__" "$file" | cut -d: -f1)
-    head -n "$((line_num - 1))" "$file"
+    head -n "$((start_line - 1))" "$file"
 
     # Print the heredoc with embedded docs
     echo "  cat <<'__BASHUNIT_DOCS_EOF__'"
@@ -148,10 +147,19 @@ function build::embed_docs() {
   chmod u+x "$file"
 }
 
+function build::assert_valid_syntax() {
+  local file=$1
+
+  if ! bash -n "$file"; then
+    echo "❌ Generated artifact failed bash -n syntax check: $file" >&2
+    exit 1
+  fi
+}
+
 function build::generate_checksum() {
   local out=$1
 
-  if [[ "$_OS" == "Windows" ]]; then
+  if [[ "$_BASHUNIT_OS" == "Windows" ]]; then
     return
   fi
 
@@ -170,34 +178,37 @@ function build::generate_checksum() {
 ######### MAIN #########
 ########################
 
-DIR="bin"
-SHOULD_VERIFY_BUILD=false
-SHOULD_CLEANUP=false
-
-for arg in "$@"; do
-  case $arg in
-  -v | --verify)
-    SHOULD_VERIFY_BUILD=true
-    ;;
-  -c | --cleanup)
-    SHOULD_CLEANUP=true
-    ;;
-  *)
-    DIR=$arg
-    ;;
-  esac
-done
+# Skip when sourced (tests source this file to exercise the functions above)
+if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
+  DIR="bin"
+  SHOULD_VERIFY_BUILD=false
+  SHOULD_CLEANUP=false
+
+  for arg in "$@"; do
+    case $arg in
+    -v | --verify)
+      SHOULD_VERIFY_BUILD=true
+      ;;
+    -c | --cleanup)
+      SHOULD_CLEANUP=true
+      ;;
+    *)
+      DIR=$arg
+      ;;
+    esac
+  done
 
-mkdir -p "$DIR"
-OUT="$DIR/bashunit"
+  mkdir -p "$DIR"
+  OUT="$DIR/bashunit"
 
-build "$OUT"
+  build "$OUT"
 
-if [[ $SHOULD_VERIFY_BUILD == true ]]; then
-  build::verify "$OUT"
-fi
+  if [[ $SHOULD_VERIFY_BUILD == true ]]; then
+    build::verify "$OUT"
+  fi
 
-if [[ $SHOULD_CLEANUP == true ]]; then
-  echo "🧹 Cleaning up build directory: $DIR"
-  rm -rf "$DIR"
+  if [[ $SHOULD_CLEANUP == true ]]; then
+    echo "🧹 Cleaning up build directory: $DIR"
+    rm -rf "$DIR"
+  fi
 fi
diff --git a/src/main.sh b/src/main.sh
index 0b031c14..35de23cb 100644
--- a/src/main.sh
+++ b/src/main.sh
@@ -92,7 +92,13 @@ function bashunit::main::cmd_test() {
       set -x
       ;;
     -S | --stop-on-failure)
-      export BASHUNIT_STOP_ON_FAILURE=true
+      # This-process-only: parallel stop uses a flag file and sync stop uses
+      # exit codes, so no child process needs it — exported (including via an
+      # allexport .env load, hence export -n) it leaked into nested bashunit
+      # runs, aborting them before rerun::persist could write
+      # .bashunit/last-failed (broke verify's acceptance tests, #834).
+      BASHUNIT_STOP_ON_FAILURE=true
+      export -n BASHUNIT_STOP_ON_FAILURE
       ;;
     -p | --parallel)
       export BASHUNIT_PARALLEL_RUN=true
@@ -151,8 +157,15 @@ function bashunit::main::cmd_test() {
       set +o allexport
       shift
       ;;
+    # Report flags are this-process-only: reports are generated by the main
+    # shell after aggregation, no child process reads these. `export -n` also
+    # strips an export attribute inherited from an allexport .env load —
+    # otherwise nested bashunit runs (bashunit's own acceptance tests, or a
+    # user's scripts under test that call bashunit) silently write their own
+    # reports over the parent's files and blow the per-run fork budget (#834).
     --log-junit | --report-junit)
-      export BASHUNIT_LOG_JUNIT="$2"
+      BASHUNIT_LOG_JUNIT="$2"
+      export -n BASHUNIT_LOG_JUNIT
       shift
       ;;
     --log-gha)
@@ -160,15 +173,18 @@ function bashunit::main::cmd_test() {
       shift
       ;;
     -r | --report-html)
-      export BASHUNIT_REPORT_HTML="$2"
+      BASHUNIT_REPORT_HTML="$2"
+      export -n BASHUNIT_REPORT_HTML
       shift
       ;;
     --report-tap)
-      export BASHUNIT_REPORT_TAP="$2"
+      BASHUNIT_REPORT_TAP="$2"
+      export -n BASHUNIT_REPORT_TAP
       shift
       ;;
     --report-json)
-      export BASHUNIT_REPORT_JSON="$2"
+      BASHUNIT_REPORT_JSON="$2"
+      export -n BASHUNIT_REPORT_JSON
       shift
       ;;
     --no-output)
diff --git a/tests/acceptance/bashunit_bench_test.sh b/tests/acceptance/bashunit_bench_test.sh
new file mode 100644
index 00000000..89e95094
--- /dev/null
+++ b/tests/acceptance/bashunit_bench_test.sh
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Regression guard for #834. The dev entrypoint never sourced src/benchmark.sh
+# (only the hand-maintained build list bundled it), so `./bashunit bench` worked
+# in the built binary but crashed with `command not found` in dev mode — and no
+# *_test.sh exercised the bench CLI path.
+function test_bench_command_runs_in_dev_mode() {
+  local fixture_dir
+  fixture_dir=$(bashunit::temp_dir)
+  printf '#!/usr/bin/env bash\nfunction bench_sample() { :; }\n' >"$fixture_dir/sample_bench.sh"
+
+  local output
+  local exit_code=0
+  output=$(./bashunit bench "$fixture_dir/sample_bench.sh" 2>&1) || exit_code=$?
+
+  assert_equals 0 "$exit_code"
+  assert_not_contains "command not found" "$output"
+  assert_contains "bench_sample" "$output"
+}
diff --git a/tests/acceptance/bashunit_flag_env_leak_test.sh b/tests/acceptance/bashunit_flag_env_leak_test.sh
new file mode 100644
index 00000000..480984a2
--- /dev/null
+++ b/tests/acceptance/bashunit_flag_env_leak_test.sh
@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Regression guard for #834. Run-mode flags (--stop-on-failure and the report
+# writers) used to be exported, so nested bashunit runs — bashunit's own
+# acceptance tests under `build.sh --verify`, or a user's scripts under test
+# that call bashunit — inherited them: nested runs aborted before persisting
+# the rerun cache, wrote their own reports over the parent's files, and blew
+# the per-run fork budget.
+function test_run_mode_flags_do_not_leak_into_nested_runs() {
+  local dir
+  dir=$(bashunit::temp_dir)
+
+  local output
+  local exit_code=0
+  output=$(./bashunit --no-parallel --skip-env-file \
+    --stop-on-failure \
+    --log-junit "$dir/log-junit.xml" \
+    --report-html "$dir/report.html" \
+    --report-tap "$dir/report.tap" \
+    --report-json "$dir/report.json" \
+    tests/acceptance/fixtures/flag_env_leak/leak_probe.sh 2>&1) || exit_code=$?
+
+  assert_equals 0 "$exit_code"
+  assert_contains "1 passed" "$output"
+}
diff --git a/tests/acceptance/fixtures/flag_env_leak/leak_probe.sh b/tests/acceptance/fixtures/flag_env_leak/leak_probe.sh
new file mode 100644
index 00000000..baaadbb3
--- /dev/null
+++ b/tests/acceptance/fixtures/flag_env_leak/leak_probe.sh
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+# Probe used by bashunit_flag_env_leak_test.sh: fails if any run-mode flag of
+# the parent bashunit process leaked into this (nested) run's environment.
+function test_run_mode_flags_are_not_in_the_environment() {
+  local leaked
+  leaked="$(env | grep -E '^BASHUNIT_(STOP_ON_FAILURE|LOG_JUNIT|REPORT_HTML|REPORT_TAP|REPORT_JSON)=' || true)"
+
+  assert_empty "$leaked"
+}
diff --git a/tests/unit/benchmark_test.sh b/tests/unit/benchmark_test.sh
index 19ab528e..30758da0 100755
--- a/tests/unit/benchmark_test.sh
+++ b/tests/unit/benchmark_test.sh
@@ -1,10 +1,6 @@
 #!/usr/bin/env bash
 # shellcheck disable=SC2329 # Mock functions are invoked indirectly by tested code
 
-function set_up_before_script() {
-  source "$BASHUNIT_ROOT_DIR/src/benchmark.sh"
-}
-
 function set_up() {
   SCRIPT="tests/benchmark/fixtures/bashunit_sleep_bench.sh"
 }
diff --git a/tests/unit/build_test.sh b/tests/unit/build_test.sh
index 8c52416e..cabff116 100644
--- a/tests/unit/build_test.sh
+++ b/tests/unit/build_test.sh
@@ -11,8 +11,8 @@ function src_files_sourced_by_entrypoint() {
   grep -oE 'src/[a-zA-Z0-9_/]+\.sh' "$ROOT_DIR/bashunit" | grep -v '^src/dev/' | sort -u
 }
 
-function src_files_in_build() {
-  grep -oE 'src/[a-zA-Z0-9_/]+\.sh' "$ROOT_DIR/build.sh" | sort -u
+function build_dependencies() {
+  (cd "$ROOT_DIR" && bash -c 'source ./build.sh && build::dependencies')
 }
 
 # Every src file the dev entrypoint sources (except dev-only helpers) must also be
@@ -20,11 +20,101 @@ function src_files_in_build() {
 # single-file binary (regressions: bench #0.31.0, watch #735).
 function test_build_bundles_every_src_file_sourced_by_entrypoint() {
   local missing
-  missing=$(comm -23 <(src_files_sourced_by_entrypoint) <(src_files_in_build))
+  missing=$(comm -23 <(src_files_sourced_by_entrypoint) <(build_dependencies | sort -u))
 
   assert_empty "$missing"
 }
 
+# The reverse direction: the build must not bundle files the entrypoint does not
+# source (a stale hand-maintained list shipped benchmark.sh while dev mode lacked
+# it — the two must stay a single source of truth).
+function test_build_bundles_only_files_sourced_by_entrypoint() {
+  local extra
+  extra=$(comm -13 <(src_files_sourced_by_entrypoint) <(build_dependencies | sort -u))
+
+  assert_empty "$extra"
+}
+
+function test_build_dependencies_include_benchmark() {
+  assert_contains "src/benchmark.sh" "$(build_dependencies)"
+}
+
+function test_build_script_is_sourceable_without_running_a_build() {
+  local output
+  output=$(cd "$ROOT_DIR" && bash -c 'source ./build.sh && declare -F build::verify' 2>&1)
+
+  assert_not_contains "Generating" "$output"
+  assert_contains "build::verify" "$output"
+}
+
+function test_build_verify_exits_nonzero_when_suite_fails() {
+  local fake_dir
+  fake_dir=$(bashunit::temp_dir)
+  printf '#!/usr/bin/env bash\nexit 1\n' >"$fake_dir/bashunit"
+  chmod +x "$fake_dir/bashunit"
+
+  local exit_code=0
+  (cd "$ROOT_DIR" && bash -c 'source ./build.sh && build::verify "$1"' _ "$fake_dir/bashunit") \
+    >/dev/null 2>&1 || exit_code=$?
+
+  assert_not_equals 0 "$exit_code"
+}
+
+function test_build_verify_succeeds_when_suite_passes() {
+  local fake_dir
+  fake_dir=$(bashunit::temp_dir)
+  printf '#!/usr/bin/env bash\nexit 0\n' >"$fake_dir/bashunit"
+  chmod +x "$fake_dir/bashunit"
+
+  local output
+  local exit_code=0
+  output=$(cd "$ROOT_DIR" && bash -c 'source ./build.sh && build::verify "$1"' _ "$fake_dir/bashunit" 2>&1) \
+    || exit_code=$?
+
+  assert_equals 0 "$exit_code"
+  assert_contains "verified" "$output"
+}
+
+function test_build_embed_docs_fails_on_missing_markers() {
+  local file
+  file=$(bashunit::temp_file)
+  printf '#!/usr/bin/env bash\necho hi\n' >"$file"
+
+  local exit_code=0
+  (cd "$ROOT_DIR" && bash -c 'source ./build.sh && build::embed_docs "$1"' _ "$file") \
+    >/dev/null 2>&1 || exit_code=$?
+
+  assert_not_equals 0 "$exit_code"
+  # The artifact must not be replaced with a truncated file on failure.
+  assert_contains "echo hi" "$(cat "$file")"
+}
+
+function test_build_process_file_embeds_a_file_only_once() {
+  local dir
+  dir=$(bashunit::temp_dir)
+  printf '#!/usr/bin/env bash\nsource ./a.sh\nsource ./b.sh\n' >"$dir/root.sh"
+  printf '#!/usr/bin/env bash\nsource ./common.sh\n' >"$dir/a.sh"
+  printf '#!/usr/bin/env bash\nsource ./common.sh\n' >"$dir/b.sh"
+  printf '#!/usr/bin/env bash\nfunction common_fn() { :; }\n' >"$dir/common.sh"
+
+  (cd "$ROOT_DIR" && bash -c 'source ./build.sh && build::process_file "$1" "$2"' _ "$dir/root.sh" "$dir/out.tmp") \
+    >/dev/null 2>&1
+
+  assert_equals "1" "$(grep -c '^# common.sh$' "$dir/out.tmp")"
+}
+
+function test_build_assert_valid_syntax_rejects_broken_file() {
+  local file
+  file=$(bashunit::temp_file)
+  printf '#!/usr/bin/env bash\nif then fi (\n' >"$file"
+
+  local exit_code=0
+  (cd "$ROOT_DIR" && bash -c 'source ./build.sh && build::assert_valid_syntax "$1"' _ "$file") \
+    >/dev/null 2>&1 || exit_code=$?
+
+  assert_not_equals 0 "$exit_code"
+}
+
 function test_built_binary_defines_watch_run() {
   local build_dir
   build_dir=$(bashunit::temp_dir)
@@ -34,3 +124,15 @@ function test_built_binary_defines_watch_run() {
   assert_file_exists "$build_dir/bashunit"
   assert_equals "1" "$(grep -c 'function bashunit::watch::run()' "$build_dir/bashunit")"
 }
+
+function test_built_binary_embeds_each_src_file_exactly_once() {
+  local build_dir
+  build_dir=$(bashunit::temp_dir)
+
+  (cd "$ROOT_DIR" && bash build.sh "$build_dir") >/dev/null 2>&1
+
+  local duplicated
+  duplicated=$(grep -E '^# [a-z_]+\.sh$' "$build_dir/bashunit" | sort | uniq -d)
+
+  assert_empty "$duplicated"
+}
diff --git a/tests/unit/check_os_test.sh b/tests/unit/check_os_test.sh
index ab488eed..8cd9c5c3 100644
--- a/tests/unit/check_os_test.sh
+++ b/tests/unit/check_os_test.sh
@@ -81,7 +81,11 @@ function test_not_alpine_is_not_busybox() {
 function test_module_load_detects_os_with_a_single_uname_call() {
   bashunit::spy uname
 
-  source "$BASHUNIT_ROOT_DIR/src/check_os.sh"
+  # Resolve src relative to this test file, not the running binary:
+  # under `build.sh --verify` the built bashunit lives in a folder
+  # without src/, and sourcing through $BASHUNIT_ROOT_DIR crashed
+  # the whole verification run (silently, until #834 gated it).
+  source "$(dirname "${BASH_SOURCE[0]}")/../../src/check_os.sh"
 
   assert_have_been_called_times 1 uname
 }
diff --git a/tests/unit/coverage_percent_test.sh b/tests/unit/coverage_percent_test.sh
index 148299b1..6b0f8839 100644
--- a/tests/unit/coverage_percent_test.sh
+++ b/tests/unit/coverage_percent_test.sh
@@ -3,7 +3,9 @@
 # Tests for tools/coverage_percent.sh: extract a single rounded coverage
 # percentage from an LCOV report by summing the per-section LH/LF records.
 
-COVERAGE_PERCENT_SCRIPT="${BASHUNIT_ROOT_DIR:-.}/tools/coverage_percent.sh"
+# cwd-relative (repo root), not $BASHUNIT_ROOT_DIR: under `build.sh --verify`
+# the running binary's root dir has no tools/ (#834).
+COVERAGE_PERCENT_SCRIPT="tools/coverage_percent.sh"
 
 function test_coverage_percent_sums_lh_over_lf() {
   local lcov
diff --git a/tests/unit/globals_test.sh b/tests/unit/globals_test.sh
index bbcbcbbc..966c9e4d 100644
--- a/tests/unit/globals_test.sh
+++ b/tests/unit/globals_test.sh
@@ -30,8 +30,15 @@ function test_globals_current_filename() {
   assert_same "globals_test.sh" "$(bashunit::current_filename)"
 }
 
+# Indirection keeps the observed caller frame inside this file: called directly
+# from a test, caller_filename reports the framework's own source layout, which
+# differs between a repo checkout (./src) and the built single-file binary (#834).
+function globals_test::call_caller_filename() {
+  bashunit::caller_filename
+}
+
 function test_globals_caller_filename() {
-  assert_same "./src" "$(bashunit::caller_filename)"
+  assert_same "tests/unit" "$(globals_test::call_caller_filename)"
 }
 
 function test_globals_caller_line() {
diff --git a/tests/unit/helpers_test.sh b/tests/unit/helpers_test.sh
index 01da1734..ea3cd8fb 100644
--- a/tests/unit/helpers_test.sh
+++ b/tests/unit/helpers_test.sh
@@ -435,9 +435,11 @@ function test_normalize_test_function_name_with_interpolation() {
 }
 
 function helpers_test::find_total_in_subshell() {
-  # "bashunit::helper::find_total_tests" needs the "data_set" function, so we have to source globals.sh first
+  # "bashunit::helper::find_total_tests" needs the "data_set" function, so we have to source globals.sh first.
+  # Paths are cwd-relative (repo root), not $BASHUNIT_ROOT_DIR: under `build.sh --verify`
+  # the running binary's root dir has no src/ (#834).
   bash -c 'source src/globals.sh; source "$1"; shift; bashunit::helper::find_total_tests "$@"' \
-    bash "$BASHUNIT_ROOT_DIR/src/helpers.sh" "$@"
+    bash "src/helpers.sh" "$@"
 }
 
 function test_find_total_tests_no_files() {
diff --git a/tests/unit/learn_test.sh b/tests/unit/learn_test.sh
index 80d470bb..ac14b5ac 100644
--- a/tests/unit/learn_test.sh
+++ b/tests/unit/learn_test.sh
@@ -11,8 +11,9 @@ set -euo pipefail
 function _learn_in_sandbox() {
   local sandbox root_dir
   sandbox="$(bashunit::temp_dir)"
-  # BASHUNIT_ROOT_DIR may be relative (e.g. "."); resolve it before cd-ing away.
-  root_dir="$(cd "$BASHUNIT_ROOT_DIR" && pwd)"
+  # Resolve the repo root from this test file, not $BASHUNIT_ROOT_DIR: under
+  # `build.sh --verify` the running binary's root dir has no src/ (#834).
+  root_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
   (
     cd "$sandbox" &&
       HOME="$sandbox" bash -c '