From 778770b4d96fe58361a782b892a35cdf09082962 Mon Sep 17 00:00:00 2001
From: Yan Pujante <yan@pongasoft.com>
Date: Wed, 14 Feb 2024 07:06:15 -0800
Subject: [PATCH 1/7] embuilder supports external ports

---
 embuilder.py                  | 14 ++++++++++++++
 test/other/ports/external.py  |  7 +++++--
 test/test_other.py            | 25 +++++++++++++++++++++++++
 tools/ports/__init__.py       | 23 +++++++++++------------
 tools/ports/contrib/README.md |  4 ++--
 tools/ports/contrib/glfw3.py  |  4 ++--
 tools/ports/sdl2_image.py     |  2 +-
 7 files changed, 60 insertions(+), 19 deletions(-)

diff --git a/embuilder.py b/embuilder.py
index 917a0361c123d..ecced2a0ea22e 100755
--- a/embuilder.py
+++ b/embuilder.py
@@ -169,6 +169,10 @@ def get_all_tasks():
   return get_system_tasks()[1] + PORTS
 
 
+def handle_port_error(arg, message):
+  raise Exception(f'Build target invalid `{arg}` | {message}')
+
+
 def main():
   all_build_start_time = time.time()
 
@@ -289,6 +293,16 @@ def main():
         clear_port(what)
       if do_build:
         build_port(what)
+    elif ':' in what or what.endswith('.py'):
+      try:
+        name = ports.handle_use_port_arg(settings, what, lambda message: handle_port_error(what, message))
+      except Exception as e:
+        logger.error(str(e))
+        return 1
+      if do_clear:
+        clear_port(name)
+      if do_build:
+        build_port(name)
     else:
       logger.error('unfamiliar build target: ' + what)
       return 1
diff --git a/test/other/ports/external.py b/test/other/ports/external.py
index 0ca8eabc8b0f6..3df5adb6c190d 100644
--- a/test/other/ports/external.py
+++ b/test/other/ports/external.py
@@ -23,7 +23,10 @@
 
 
 def get_lib_name(settings):
-  return 'lib_external.a'
+  if opts['dependency']:
+    return f'lib_external-{opts["dependency"]}.a'
+  else:
+    return 'lib_external.a'
 
 
 def get(ports, settings, shared):
@@ -58,5 +61,5 @@ def process_dependencies(settings):
     deps.append(opts['dependency'])
 
 
-def handle_options(options):
+def handle_options(options, error_handler):
   opts.update(options)
diff --git a/test/test_other.py b/test/test_other.py
index 77fce4d6e3795..e5762c2f09b2b 100644
--- a/test/test_other.py
+++ b/test/test_other.py
@@ -2418,6 +2418,31 @@ def test_external_ports(self):
     self.assertFalse(os.path.exists('a4.out.js'))
     self.assertContained('Unknown dependency `invalid` for port `external`', stderr)
 
+  @crossplatform
+  def test_embuilder_with_use_port_syntax(self):
+    if config.FROZEN_CACHE:
+      self.skipTest("test doesn't work with frozen cache")
+    self.run_process([EMBUILDER, 'build', 'sdl2_image:formats=png,jpg', '--force'])
+    self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'libSDL2_image_jpg-png.a'))
+
+  @crossplatform
+  def test_embuilder_external_ports(self):
+    if config.FROZEN_CACHE:
+      self.skipTest("test doesn't work with frozen cache")
+    simple_port_path = test_file("other/ports/simple.py")
+    # embuilder handles external port target that ends with .py
+    self.run_process([EMBUILDER, 'build', f'{simple_port_path}', '--force'])
+    self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'lib_simple.a'))
+    # embuilder handles external port target that contains port options
+    external_port_path = test_file("other/ports/external.py")
+    self.run_process([EMBUILDER, 'build', f'{external_port_path}:value1=12:value2=36', '--force'])
+    self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'lib_external.a'))
+    # embuilder handles external port target that contains port options (influences library name,
+    # like sdl2_image:formats=png)
+    external_port_path = test_file("other/ports/external.py")
+    self.run_process([EMBUILDER, 'build', f'{external_port_path}:dependency=sdl2', '--force'])
+    self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'lib_external-sdl2.a'))
+
   def test_link_memcpy(self):
     # memcpy can show up *after* optimizations, so after our opportunity to link in libc, so it must be special-cased
     create_file('main.c', r'''
diff --git a/tools/ports/__init__.py b/tools/ports/__init__.py
index 18ce4dd995f29..9be51f139b5f4 100644
--- a/tools/ports/__init__.py
+++ b/tools/ports/__init__.py
@@ -408,11 +408,9 @@ def add_deps(node):
     add_deps(port)
 
 
-def handle_use_port_error(arg, message):
-  utils.exit_with_error(f'Error with `--use-port={arg}` | {message}')
-
-
-def handle_use_port_arg(settings, arg):
+def handle_use_port_arg(settings, arg, error_handler = None):
+  if not error_handler:
+    error_handler = lambda message: utils.exit_with_error(f'Error with `--use-port={arg}` | {message}')
   # Ignore ':' in first or second char of string since we could be dealing with a windows drive separator
   pos = arg.find(':', 2)
   if pos != -1:
@@ -422,27 +420,28 @@ def handle_use_port_arg(settings, arg):
   if name.endswith('.py'):
     port_file_path = name
     if not os.path.isfile(port_file_path):
-      handle_use_port_error(arg, f'not a valid port path: {port_file_path}')
+      error_handler(f'not a valid port path: {port_file_path}')
     name = load_port_by_path(port_file_path)
   elif name not in ports_by_name:
-    handle_use_port_error(arg, f'invalid port name: `{name}`')
+    error_handler(f'invalid port name: `{name}`')
   ports_needed.add(name)
   if options:
     port = ports_by_name[name]
     if not hasattr(port, 'handle_options'):
-      handle_use_port_error(arg, f'no options available for port `{name}`')
+      error_handler(f'no options available for port `{name}`')
     else:
       options_dict = {}
       for name_value in options.split(':'):
         nv = name_value.split('=', 1)
         if len(nv) != 2:
-          handle_use_port_error(arg, f'`{name_value}` is missing a value')
+          error_handler(f'`{name_value}` is missing a value')
         if nv[0] not in port.OPTIONS:
-          handle_use_port_error(arg, f'`{nv[0]}` is not supported; available options are {port.OPTIONS}')
+          error_handler(f'`{nv[0]}` is not supported; available options are {port.OPTIONS}')
         if nv[0] in options_dict:
-          handle_use_port_error(arg, f'duplicate option `{nv[0]}`')
+          error_handler(f'duplicate option `{nv[0]}`')
         options_dict[nv[0]] = nv[1]
-      port.handle_options(options_dict)
+      port.handle_options(options_dict, error_handler)
+  return name
 
 
 def get_needed_ports(settings):
diff --git a/tools/ports/contrib/README.md b/tools/ports/contrib/README.md
index 670b53cbd90ab..e8637123a8df0 100644
--- a/tools/ports/contrib/README.md
+++ b/tools/ports/contrib/README.md
@@ -23,9 +23,9 @@ additional components:
 
 1. A handler function defined this way:
 ```python
-def handle_options(options):
+def handle_options(options, error_handler):
   # options is of type Dict[str, str]
-  # in case of error, use utils.exit_with_error('error message')
+  # in case of error, use error_handler('error message')
 ```
 2. A dictionary called `OPTIONS` (type `Dict[str, str]`) where each key is the 
    name of the option and the value is a short description of what it does 
diff --git a/tools/ports/contrib/glfw3.py b/tools/ports/contrib/glfw3.py
index 7e83fdd301280..e13682e5135b6 100644
--- a/tools/ports/contrib/glfw3.py
+++ b/tools/ports/contrib/glfw3.py
@@ -83,9 +83,9 @@ def process_args(ports):
   return ['-isystem', ports.get_include_dir('contrib.glfw3')]
 
 
-def handle_options(options):
+def handle_options(options, error_handler):
   for option, value in options.items():
     if value.lower() in {'true', 'false'}:
       opts[option] = value.lower() == 'true'
     else:
-      utils.exit_with_error(f'{option} is expecting a boolean, got {value}')
+      error_handler(f'{option} is expecting a boolean, got {value}')
diff --git a/tools/ports/sdl2_image.py b/tools/ports/sdl2_image.py
index 0adf74a0e5660..aef973eba3471 100644
--- a/tools/ports/sdl2_image.py
+++ b/tools/ports/sdl2_image.py
@@ -88,7 +88,7 @@ def process_dependencies(settings):
     settings.USE_LIBJPEG = 1
 
 
-def handle_options(options):
+def handle_options(options, error_handler):
   opts['formats'].update({format.lower().strip() for format in options['formats'].split(',')})
 
 

From 2b382ed09e2f06385626de04a47dd08014b068b1 Mon Sep 17 00:00:00 2001
From: Yan Pujante <yan@pongasoft.com>
Date: Wed, 14 Feb 2024 07:14:31 -0800
Subject: [PATCH 2/7] removed unnecessary import

---
 tools/ports/contrib/glfw3.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tools/ports/contrib/glfw3.py b/tools/ports/contrib/glfw3.py
index e13682e5135b6..fe46d695e75e6 100644
--- a/tools/ports/contrib/glfw3.py
+++ b/tools/ports/contrib/glfw3.py
@@ -4,7 +4,6 @@
 # found in the LICENSE file.
 
 import os
-from tools import utils
 from typing import Dict
 
 TAG = '1.0.4'

From 6a97d807ffe5ea8421114159efc3e15db213fe30 Mon Sep 17 00:00:00 2001
From: Yan Pujante <yan@pongasoft.com>
Date: Wed, 14 Feb 2024 07:22:50 -0800
Subject: [PATCH 3/7] flake8 issues

---
 tools/ports/__init__.py | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tools/ports/__init__.py b/tools/ports/__init__.py
index 9be51f139b5f4..c93e756ecb797 100644
--- a/tools/ports/__init__.py
+++ b/tools/ports/__init__.py
@@ -408,9 +408,14 @@ def add_deps(node):
     add_deps(port)
 
 
-def handle_use_port_arg(settings, arg, error_handler = None):
+def handle_use_port_error(arg, message):
+  utils.exit_with_error(f'Error with `--use-port={arg}` | {message}')
+
+
+def handle_use_port_arg(settings, arg, error_handler=None):
   if not error_handler:
-    error_handler = lambda message: utils.exit_with_error(f'Error with `--use-port={arg}` | {message}')
+    def error_handler(message):
+      handle_use_port_error(arg, message)
   # Ignore ':' in first or second char of string since we could be dealing with a windows drive separator
   pos = arg.find(':', 2)
   if pos != -1:

From 45d2fda62e1f88d7c5b7459ed5e0522b76866510 Mon Sep 17 00:00:00 2001
From: Yan Pujante <yan@pongasoft.com>
Date: Wed, 14 Feb 2024 08:20:23 -0800
Subject: [PATCH 4/7] simplified code

---
 embuilder.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/embuilder.py b/embuilder.py
index ecced2a0ea22e..3f22705454ffd 100755
--- a/embuilder.py
+++ b/embuilder.py
@@ -169,8 +169,8 @@ def get_all_tasks():
   return get_system_tasks()[1] + PORTS
 
 
-def handle_port_error(arg, message):
-  raise Exception(f'Build target invalid `{arg}` | {message}')
+def handle_port_error(message):
+  raise Exception(message)
 
 
 def main():
@@ -295,9 +295,9 @@ def main():
         build_port(what)
     elif ':' in what or what.endswith('.py'):
       try:
-        name = ports.handle_use_port_arg(settings, what, lambda message: handle_port_error(what, message))
+        name = ports.handle_use_port_arg(settings, what, lambda message: handle_port_error(message))
       except Exception as e:
-        logger.error(str(e))
+        logger.error(f'Build target invalid `{what}` | {e}')
         return 1
       if do_clear:
         clear_port(name)

From 4be9926d050321418f5d40e921f56ab5e0280e63 Mon Sep 17 00:00:00 2001
From: Yan Pujante <yan@pongasoft.com>
Date: Wed, 14 Feb 2024 12:27:29 -0800
Subject: [PATCH 5/7] code review

---
 embuilder.py                  | 11 ++++-------
 test/test_other.py            | 25 -------------------------
 test/test_sanity.py           | 22 ++++++++++++++++++++++
 tools/ports/contrib/README.md |  3 ++-
 tools/ports/sdl2_image.py     | 11 ++++++++++-
 5 files changed, 38 insertions(+), 34 deletions(-)

diff --git a/embuilder.py b/embuilder.py
index 3f22705454ffd..d2cbf8689f157 100755
--- a/embuilder.py
+++ b/embuilder.py
@@ -23,6 +23,7 @@
 from tools import shared
 from tools import system_libs
 from tools import ports
+from tools import utils
 from tools.settings import settings
 from tools.system_libs import USE_NINJA
 
@@ -169,8 +170,8 @@ def get_all_tasks():
   return get_system_tasks()[1] + PORTS
 
 
-def handle_port_error(message):
-  raise Exception(message)
+def handle_port_error(target, message):
+  utils.exit_with_error(f'Build target invalid `{target}` | {message}')
 
 
 def main():
@@ -294,11 +295,7 @@ def main():
       if do_build:
         build_port(what)
     elif ':' in what or what.endswith('.py'):
-      try:
-        name = ports.handle_use_port_arg(settings, what, lambda message: handle_port_error(message))
-      except Exception as e:
-        logger.error(f'Build target invalid `{what}` | {e}')
-        return 1
+      name = ports.handle_use_port_arg(settings, what, lambda message: handle_port_error(what, message))
       if do_clear:
         clear_port(name)
       if do_build:
diff --git a/test/test_other.py b/test/test_other.py
index e5762c2f09b2b..77fce4d6e3795 100644
--- a/test/test_other.py
+++ b/test/test_other.py
@@ -2418,31 +2418,6 @@ def test_external_ports(self):
     self.assertFalse(os.path.exists('a4.out.js'))
     self.assertContained('Unknown dependency `invalid` for port `external`', stderr)
 
-  @crossplatform
-  def test_embuilder_with_use_port_syntax(self):
-    if config.FROZEN_CACHE:
-      self.skipTest("test doesn't work with frozen cache")
-    self.run_process([EMBUILDER, 'build', 'sdl2_image:formats=png,jpg', '--force'])
-    self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'libSDL2_image_jpg-png.a'))
-
-  @crossplatform
-  def test_embuilder_external_ports(self):
-    if config.FROZEN_CACHE:
-      self.skipTest("test doesn't work with frozen cache")
-    simple_port_path = test_file("other/ports/simple.py")
-    # embuilder handles external port target that ends with .py
-    self.run_process([EMBUILDER, 'build', f'{simple_port_path}', '--force'])
-    self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'lib_simple.a'))
-    # embuilder handles external port target that contains port options
-    external_port_path = test_file("other/ports/external.py")
-    self.run_process([EMBUILDER, 'build', f'{external_port_path}:value1=12:value2=36', '--force'])
-    self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'lib_external.a'))
-    # embuilder handles external port target that contains port options (influences library name,
-    # like sdl2_image:formats=png)
-    external_port_path = test_file("other/ports/external.py")
-    self.run_process([EMBUILDER, 'build', f'{external_port_path}:dependency=sdl2', '--force'])
-    self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'lib_external-sdl2.a'))
-
   def test_link_memcpy(self):
     # memcpy can show up *after* optimizations, so after our opportunity to link in libc, so it must be special-cased
     create_file('main.c', r'''
diff --git a/test/test_sanity.py b/test/test_sanity.py
index 0375e28237a9d..95aab038bdf43 100644
--- a/test/test_sanity.py
+++ b/test/test_sanity.py
@@ -748,6 +748,28 @@ def test_embuilder_wildcards(self):
     self.run_process([EMBUILDER, 'build', 'libwebgpu*'])
     self.assertGreater(len(glob.glob(glob_match)), 3)
 
+  def test_embuilder_with_use_port_syntax(self):
+    restore_and_set_up()
+    self.run_process([EMBUILDER, 'build', 'sdl2_image:formats=png,jpg', '--force'])
+    self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'libSDL2_image_jpg-png.a'))
+    self.assertContained('Build target invalid `sdl2_image:formats=invalid` | invalid is not a supported format', self.do([EMBUILDER, 'build', 'sdl2_image:formats=invalid', '--force']))
+
+  def test_embuilder_external_ports(self):
+    restore_and_set_up()
+    simple_port_path = test_file("other/ports/simple.py")
+    # embuilder handles external port target that ends with .py
+    self.run_process([EMBUILDER, 'build', f'{simple_port_path}', '--force'])
+    self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'lib_simple.a'))
+    # embuilder handles external port target that contains port options
+    external_port_path = test_file("other/ports/external.py")
+    self.run_process([EMBUILDER, 'build', f'{external_port_path}:value1=12:value2=36', '--force'])
+    self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'lib_external.a'))
+    # embuilder handles external port target that contains port options (influences library name,
+    # like sdl2_image:formats=png)
+    external_port_path = test_file("other/ports/external.py")
+    self.run_process([EMBUILDER, 'build', f'{external_port_path}:dependency=sdl2', '--force'])
+    self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'lib_external-sdl2.a'))
+
   def test_binaryen_version(self):
     restore_and_set_up()
     with open(EM_CONFIG, 'a') as f:
diff --git a/tools/ports/contrib/README.md b/tools/ports/contrib/README.md
index e8637123a8df0..42fa65edc10da 100644
--- a/tools/ports/contrib/README.md
+++ b/tools/ports/contrib/README.md
@@ -26,6 +26,7 @@ additional components:
 def handle_options(options, error_handler):
   # options is of type Dict[str, str]
   # in case of error, use error_handler('error message')
+  # note that error_handler is guaranteed to never return
 ```
 2. A dictionary called `OPTIONS` (type `Dict[str, str]`) where each key is the 
    name of the option and the value is a short description of what it does 
@@ -33,7 +34,7 @@ def handle_options(options, error_handler):
 When emscripten detects that options have been provided, it parses them and
 check that they are valid option names for this port (using `OPTIONS`). It then
 calls the handler function with these (valid) options. If you detect an error
-with a value, you should use `tools.utils.exit_with_error` to report the 
+with a value, you should use the error handler provided to report the 
 failure.
 
 > ### Note
diff --git a/tools/ports/sdl2_image.py b/tools/ports/sdl2_image.py
index aef973eba3471..2addb21b4d02f 100644
--- a/tools/ports/sdl2_image.py
+++ b/tools/ports/sdl2_image.py
@@ -19,6 +19,9 @@
   'formats': 'A comma separated list of formats (ex: --use-port=sdl2_image:formats=png,jpg)'
 }
 
+SUPPORTED_FORMATS = {'avif', 'bmp', 'gif', 'jpg', 'jxl', 'lbm', 'pcx', 'png',
+                     'pnm', 'qoi', 'svg', 'tga', 'tif', 'webp', 'xcf', 'xpm', 'xv'}
+
 # user options (from --use-port)
 opts: Dict[str, Set] = {
   'formats': set()
@@ -89,7 +92,13 @@ def process_dependencies(settings):
 
 
 def handle_options(options, error_handler):
-  opts['formats'].update({format.lower().strip() for format in options['formats'].split(',')})
+  formats = options['formats'].split(',')
+  for format in formats:
+    format = format.lower().strip()
+    if format not in SUPPORTED_FORMATS:
+      error_handler(f'{format} is not a supported format')
+    else:
+      opts['formats'].add(format)
 
 
 def show():

From a277612523adff25ce7e4959841b246ba806453a Mon Sep 17 00:00:00 2001
From: Yan Pujante <yan@pongasoft.com>
Date: Wed, 14 Feb 2024 12:46:24 -0800
Subject: [PATCH 6/7] fixed error message per review

---
 embuilder.py        | 2 +-
 test/test_sanity.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/embuilder.py b/embuilder.py
index d2cbf8689f157..c4a77cbe1b644 100755
--- a/embuilder.py
+++ b/embuilder.py
@@ -171,7 +171,7 @@ def get_all_tasks():
 
 
 def handle_port_error(target, message):
-  utils.exit_with_error(f'Build target invalid `{target}` | {message}')
+  utils.exit_with_error(f'Error building port `{target}` | {message}')
 
 
 def main():
diff --git a/test/test_sanity.py b/test/test_sanity.py
index 95aab038bdf43..f037b9c390610 100644
--- a/test/test_sanity.py
+++ b/test/test_sanity.py
@@ -752,7 +752,7 @@ def test_embuilder_with_use_port_syntax(self):
     restore_and_set_up()
     self.run_process([EMBUILDER, 'build', 'sdl2_image:formats=png,jpg', '--force'])
     self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'libSDL2_image_jpg-png.a'))
-    self.assertContained('Build target invalid `sdl2_image:formats=invalid` | invalid is not a supported format', self.do([EMBUILDER, 'build', 'sdl2_image:formats=invalid', '--force']))
+    self.assertContained('Error building port `sdl2_image:formats=invalid` | invalid is not a supported format', self.do([EMBUILDER, 'build', 'sdl2_image:formats=invalid', '--force']))
 
   def test_embuilder_external_ports(self):
     restore_and_set_up()

From f8b1879f93cc8ee47724a471c44d6e1f6e30deb6 Mon Sep 17 00:00:00 2001
From: Yan Pujante <yan@pongasoft.com>
Date: Wed, 14 Feb 2024 12:59:06 -0800
Subject: [PATCH 7/7] fixed error message capital

---
 embuilder.py            |  2 +-
 test/test_other.py      | 12 ++++++------
 test/test_sanity.py     |  2 +-
 tools/ports/__init__.py |  4 ++--
 4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/embuilder.py b/embuilder.py
index c4a77cbe1b644..3c770a7d05e96 100755
--- a/embuilder.py
+++ b/embuilder.py
@@ -171,7 +171,7 @@ def get_all_tasks():
 
 
 def handle_port_error(target, message):
-  utils.exit_with_error(f'Error building port `{target}` | {message}')
+  utils.exit_with_error(f'error building port `{target}` | {message}')
 
 
 def main():
diff --git a/test/test_other.py b/test/test_other.py
index 7a8f24abecab4..7c0759dc7c9e6 100644
--- a/test/test_other.py
+++ b/test/test_other.py
@@ -2416,7 +2416,7 @@ def test_external_ports(self):
     # testing invalid dependency
     stderr = self.expect_fail([EMCC, test_file('other/test_external_ports.c'), f'--use-port={external_port_path}:dependency=invalid', '-o', 'a4.out.js'])
     self.assertFalse(os.path.exists('a4.out.js'))
-    self.assertContained('Unknown dependency `invalid` for port `external`', stderr)
+    self.assertContained('unknown dependency `invalid` for port `external`', stderr)
 
   def test_link_memcpy(self):
     # memcpy can show up *after* optimizations, so after our opportunity to link in libc, so it must be special-cased
@@ -14557,16 +14557,16 @@ def test_js_preprocess_pre_post(self):
   def test_use_port_errors(self, compiler):
     stderr = self.expect_fail([compiler, test_file('hello_world.c'), '--use-port=invalid', '-o', 'out.js'])
     self.assertFalse(os.path.exists('out.js'))
-    self.assertContained('Error with `--use-port=invalid` | invalid port name: `invalid`', stderr)
+    self.assertContained('error with `--use-port=invalid` | invalid port name: `invalid`', stderr)
     stderr = self.expect_fail([compiler, test_file('hello_world.c'), '--use-port=sdl2:opt1=v1', '-o', 'out.js'])
     self.assertFalse(os.path.exists('out.js'))
-    self.assertContained('Error with `--use-port=sdl2:opt1=v1` | no options available for port `sdl2`', stderr)
+    self.assertContained('error with `--use-port=sdl2:opt1=v1` | no options available for port `sdl2`', stderr)
     stderr = self.expect_fail([compiler, test_file('hello_world.c'), '--use-port=sdl2_image:format=jpg', '-o', 'out.js'])
     self.assertFalse(os.path.exists('out.js'))
-    self.assertContained('Error with `--use-port=sdl2_image:format=jpg` | `format` is not supported', stderr)
+    self.assertContained('error with `--use-port=sdl2_image:format=jpg` | `format` is not supported', stderr)
     stderr = self.expect_fail([compiler, test_file('hello_world.c'), '--use-port=sdl2_image:formats', '-o', 'out.js'])
     self.assertFalse(os.path.exists('out.js'))
-    self.assertContained('Error with `--use-port=sdl2_image:formats` | `formats` is missing a value', stderr)
+    self.assertContained('error with `--use-port=sdl2_image:formats` | `formats` is missing a value', stderr)
     stderr = self.expect_fail([compiler, test_file('hello_world.c'), '--use-port=sdl2_image:formats=jpg:formats=png', '-o', 'out.js'])
     self.assertFalse(os.path.exists('out.js'))
-    self.assertContained('Error with `--use-port=sdl2_image:formats=jpg:formats=png` | duplicate option `formats`', stderr)
+    self.assertContained('error with `--use-port=sdl2_image:formats=jpg:formats=png` | duplicate option `formats`', stderr)
diff --git a/test/test_sanity.py b/test/test_sanity.py
index f037b9c390610..e1de89dd12711 100644
--- a/test/test_sanity.py
+++ b/test/test_sanity.py
@@ -752,7 +752,7 @@ def test_embuilder_with_use_port_syntax(self):
     restore_and_set_up()
     self.run_process([EMBUILDER, 'build', 'sdl2_image:formats=png,jpg', '--force'])
     self.assertExists(os.path.join(config.CACHE, 'sysroot', 'lib', 'wasm32-emscripten', 'libSDL2_image_jpg-png.a'))
-    self.assertContained('Error building port `sdl2_image:formats=invalid` | invalid is not a supported format', self.do([EMBUILDER, 'build', 'sdl2_image:formats=invalid', '--force']))
+    self.assertContained('error building port `sdl2_image:formats=invalid` | invalid is not a supported format', self.do([EMBUILDER, 'build', 'sdl2_image:formats=invalid', '--force']))
 
   def test_embuilder_external_ports(self):
     restore_and_set_up()
diff --git a/tools/ports/__init__.py b/tools/ports/__init__.py
index c93e756ecb797..2241991ece9f6 100644
--- a/tools/ports/__init__.py
+++ b/tools/ports/__init__.py
@@ -398,7 +398,7 @@ def add_deps(node):
     node.process_dependencies(settings)
     for d in node.deps:
       if d not in ports_by_name:
-        utils.exit_with_error(f'Unknown dependency `{d}` for port `{node.name}`')
+        utils.exit_with_error(f'unknown dependency `{d}` for port `{node.name}`')
       dep = ports_by_name[d]
       if dep not in port_set:
         port_set.add(dep)
@@ -409,7 +409,7 @@ def add_deps(node):
 
 
 def handle_use_port_error(arg, message):
-  utils.exit_with_error(f'Error with `--use-port={arg}` | {message}')
+  utils.exit_with_error(f'error with `--use-port={arg}` | {message}')
 
 
 def handle_use_port_arg(settings, arg, error_handler=None):