diff --git a/src/mx/_impl/mx.py b/src/mx/_impl/mx.py
index aa390a14..8a8e25fb 100755
--- a/src/mx/_impl/mx.py
+++ b/src/mx/_impl/mx.py
@@ -7709,17 +7709,18 @@ def redirect(stream):
 
         # wait 30 seconds for the Java process to launch and report the port number
         retries = 0
+        myself = f"{self.name}[{p.pid}]"
         while self.port is None:
             retries = retries + 1
             returncode = p.poll()
             if returncode is not None:
-                raise RuntimeError('Error starting ' + self.name() + ': returncode=' + str(returncode) + '\n' + ''.join(pout))
+                raise RuntimeError(f'Error starting {myself}: returncode={returncode}\n{"".join(pout)}')
             if retries == 299:
-                warn('Killing ' + self.name() + ' after failing to see port number after nearly 30 seconds')
+                warn(f'Killing {myself} after failing to see port number after nearly 30 seconds')
                 os.kill(p.pid, signal.SIGKILL)
                 time.sleep(1.0)
             elif retries > 300:
-                raise RuntimeError('Error starting ' + self.name() + ': No port number was found in output after 30 seconds\n' + ''.join(pout))
+                raise RuntimeError(f'Error starting {myself}: No port number was found in output after 30 seconds\n{"".join(pout)}')
             else:
                 time.sleep(0.1)
 
@@ -7727,10 +7728,10 @@ def redirect(stream):
         self.closed = False
         try:
             self.connection.connect(('127.0.0.1', self.port))
-            logv('[Started ' + str(self) + ']')
+            logv(f'[Started {myself}')
             return
         except socket.error as e:
-            logv('[Error starting ' + str(self) + ': ' + str(e) + ']')
+            logv(f'[Error starting {myself}: {e}]')
             raise e
 
     def _noticePort(self, data):
@@ -7767,7 +7768,7 @@ def compile(self, compilerArgs):
                 if _opts.very_verbose:
                     retcode = detailed_retcode
                 else:
-                    log('[exit code: ' + str(retcode) + ']')
+                    log(f'[exit code: {retcode}]')
             elif retcode == 2:
                 retcode = detailed_retcode
             abort(retcode)
@@ -7780,9 +7781,9 @@ def shutdown(self):
                 self.connection.send(f'{CompilerDaemon.header_shutdown}\n'.encode('utf8'))
                 self.connection.close()
                 self.closed = True
-                logv('[Stopped ' + str(self) + ']')
+                logv(f'[Stopped {self}]')
             except socket.error as e:
-                logv('Error stopping ' + str(self) + ': ' + str(e))
+                logv(f'Error stopping {self}: {e}')
 
     def __str__(self):
         return f"{self.name()} on port {self.port} for {self.jdk} with VM args {self.jvmArgs}"
@@ -18180,7 +18181,7 @@ def alarm_handler(signum, frame):
 _CACHE_DIR = get_env('MX_CACHE_DIR', join(dot_mx_dir(), 'cache'))
 
 # The version must be updated for every PR (checked in CI) and the comment should reflect the PR's issue
-version = VersionSpec("7.25.0")  # DownloadableLibrary
+version = VersionSpec("7.25.1")  # Avoid assuming there’s a PATH variable defined
 
 _mx_start_datetime = datetime.utcnow()
 
diff --git a/src/mx/_impl/mx_proftool.py b/src/mx/_impl/mx_proftool.py
index 6d2e361c..bcaf0199 100644
--- a/src/mx/_impl/mx_proftool.py
+++ b/src/mx/_impl/mx_proftool.py
@@ -920,14 +920,6 @@ def demangled_name(self, short_class_names: bool = False):
                 return self.symbol
 
 
-def _which(executable):
-    for path in os.environ['PATH'].split(os.pathsep):
-        f = os.path.join(path.strip('"'), executable)
-        if os.path.isfile(f) and os.access(f, os.X_OK):
-            return f
-    return None
-
-
 class CppDemangler:
     """An interface for the binutils c++filt demangler, which can demangle C++ symbols."""
 
@@ -945,7 +937,7 @@ def warn_if_unsupported(cls):
     def is_supported(cls) -> bool:
         """Lazily checks whether c++filt is supported."""
         if cls._cppfilt_available is None:
-            cls._cppfilt_available = _which(cls.CPPFILT) is not None
+            cls._cppfilt_available = shutil.which(cls.CPPFILT) is not None
         return cls._cppfilt_available
 
     @classmethod
@@ -1144,7 +1136,7 @@ def __init__(self, files):
     @staticmethod
     def is_supported():
         if PerfOutput._perf_available is None:
-            PerfOutput._perf_available = _which('perf') is not None
+            PerfOutput._perf_available = shutil.which('perf') is not None
         return PerfOutput._perf_available
 
     @staticmethod