diff --git a/Library/Homebrew/brew.sh b/Library/Homebrew/brew.sh
index 1e8fb39982..762cdf2dc3 100644
--- a/Library/Homebrew/brew.sh
+++ b/Library/Homebrew/brew.sh
@@ -247,6 +247,13 @@ then
   else
     HOMEBREW_BREW_CALLER="$(readlink -f "/proc/${PPID}/exe")"
   fi
+  HOMEBREW_BREW_CALLER_CHECK_EXIT_CODE="$?"
+
+  if [[ "${HOMEBREW_BREW_CALLER_CHECK_EXIT_CODE}" -ne 0 ]]
+  then
+    # Error message already printed above when populating `HOMEBREW_BREW_CALLER`.
+    odie "failed to check the path to the parent process!"
+  fi
 
   if [[ "${HOMEBREW_BREW_CALLER:-}" != "${HOMEBREW_FORCE_BREW_WRAPPER}" ]]
   then
@@ -269,7 +276,7 @@ or that ${HOMEBREW_FORCE_BREW_WRAPPER_WITHOUT_BREW} comes before ${HOMEBREW_PREF
 EOS
   fi
 
-  unset HOMEBREW_BREW_CALLER
+  unset HOMEBREW_BREW_CALLER HOMEBREW_BREW_CALLER_CHECK_EXIT_CODE
 fi
 
 # commands that take a single or no arguments and need to write to HOMEBREW_PREFIX.
diff --git a/Library/Homebrew/utils/pid_path.rb b/Library/Homebrew/utils/pid_path.rb
index 73f7505b68..e73c088e2a 100755
--- a/Library/Homebrew/utils/pid_path.rb
+++ b/Library/Homebrew/utils/pid_path.rb
@@ -3,7 +3,7 @@
 # frozen_string_literal: true
 
 pid = ARGV[0]&.to_i
-exit 1 unless pid
+raise "Missing `pid` argument!" unless pid
 
 require "fiddle"
 
@@ -29,4 +29,8 @@ pointer_to_buffer = Fiddle::Pointer.to_ptr(buffer)
 # https://github.com/chromium/chromium/blob/86df41504a235f9369f6f53887da12a718a19db4/base/process/process_handle_mac.cc#L37-L44
 # https://github.com/apple-oss-distributions/xnu/blob/e3723e1f17661b24996789d8afc084c0c3303b26/libsyscall/wrappers/libproc/libproc.c#L263-L283
 return_value = libproc_proc_pidpath_function.call(pid, pointer_to_buffer, buffer_size)
-puts pointer_to_buffer.to_s.strip if return_value.positive?
+if return_value.positive?
+  puts pointer_to_buffer.to_s.strip
+else
+  raise "Call to `proc_pidpath` failed! `proc_pidpath` returned #{return_value}."
+end