diff --git a/Sources/Testing/ExitTests/SpawnProcess.swift b/Sources/Testing/ExitTests/SpawnProcess.swift
index 50d78010a..c5d87e6f7 100644
--- a/Sources/Testing/ExitTests/SpawnProcess.swift
+++ b/Sources/Testing/ExitTests/SpawnProcess.swift
@@ -46,9 +46,9 @@ func spawnExecutable(
 ) throws -> ProcessID {
   // Darwin and Linux differ in their optionality for the posix_spawn types we
   // use, so use this typealias to paper over the differences.
-#if SWT_TARGET_OS_APPLE
+#if SWT_TARGET_OS_APPLE || os(FreeBSD)
   typealias P<T> = T?
-#elseif os(Linux) || os(FreeBSD)
+#elseif os(Linux)
   typealias P<T> = T
 #endif
 
diff --git a/Sources/Testing/Support/Additions/CommandLineAdditions.swift b/Sources/Testing/Support/Additions/CommandLineAdditions.swift
index c354e386a..762ab7290 100644
--- a/Sources/Testing/Support/Additions/CommandLineAdditions.swift
+++ b/Sources/Testing/Support/Additions/CommandLineAdditions.swift
@@ -16,16 +16,19 @@ extension CommandLine {
     get throws {
 #if os(macOS)
       var result: String?
-      var bufferCount = UInt32(1024)
+#if DEBUG
+      var bufferCount = UInt32(1) // force looping
+#else
+      var bufferCount = UInt32(PATH_MAX)
+#endif
       while result == nil {
-        result = withUnsafeTemporaryAllocation(of: CChar.self, capacity: Int(bufferCount)) { buffer in
+        withUnsafeTemporaryAllocation(of: CChar.self, capacity: Int(bufferCount)) { buffer in
           // _NSGetExecutablePath returns 0 on success and -1 if bufferCount is
           // too small. If that occurs, we'll return nil here and loop with the
           // new value of bufferCount.
           if 0 == _NSGetExecutablePath(buffer.baseAddress, &bufferCount) {
-            return String(cString: buffer.baseAddress!)
+            result = String(cString: buffer.baseAddress!)
           }
-          return nil
         }
       }
       return result!
@@ -40,7 +43,7 @@ extension CommandLine {
       }
 #elseif os(FreeBSD)
       var mib = [CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1]
-      try mib.withUnsafeMutableBufferPointer { mib in
+      return try mib.withUnsafeMutableBufferPointer { mib in
         var bufferCount = 0
         guard 0 == sysctl(mib.baseAddress!, .init(mib.count), nil, &bufferCount, nil, 0) else {
           throw CError(rawValue: swt_errno())
@@ -53,15 +56,30 @@ extension CommandLine {
         }
       }
 #elseif os(Windows)
-      return try withUnsafeTemporaryAllocation(of: wchar_t.self, capacity: Int(MAX_PATH) * 2) { buffer in
-        guard 0 != GetModuleFileNameW(nil, buffer.baseAddress!, DWORD(buffer.count)) else {
-          throw Win32Error(rawValue: GetLastError())
-        }
-        guard let path = String.decodeCString(buffer.baseAddress!, as: UTF16.self)?.result else {
-          throw Win32Error(rawValue: DWORD(ERROR_ILLEGAL_CHARACTER))
+      var result: String?
+#if DEBUG
+      var bufferCount = Int(1) // force looping
+#else
+      var bufferCount = Int(MAX_PATH)
+#endif
+      while result == nil {
+        try withUnsafeTemporaryAllocation(of: wchar_t.self, capacity: bufferCount) { buffer in
+          SetLastError(DWORD(ERROR_SUCCESS))
+          _ = GetModuleFileNameW(nil, buffer.baseAddress!, DWORD(buffer.count))
+          switch GetLastError() {
+          case DWORD(ERROR_SUCCESS):
+            result = String.decodeCString(buffer.baseAddress!, as: UTF16.self)?.result
+            if result == nil {
+              throw Win32Error(rawValue: DWORD(ERROR_ILLEGAL_CHARACTER))
+            }
+          case DWORD(ERROR_INSUFFICIENT_BUFFER):
+            bufferCount += Int(MAX_PATH)
+          case let errorCode:
+            throw Win32Error(rawValue: errorCode)
+          }
         }
-        return path
       }
+      return result!
 #elseif os(WASI)
       // WASI does not really have the concept of a file system path to the main
       // executable, so simply return the first argument--presumably the program