fix(cli): Android SDK auto-installation failing on Windows

CHANGELOG.md

@@ -10,6 +10,7 @@
 
 ### Bug fixes
 
+* Fix the Android SDK auto-installation failing on Windows ([#6522](https://github.com/flet-dev/flet/issues/6522), [#6892](https://github.com/flet-dev/flet/pull/6892)) by @ndonkoHenri.
 * Fix `InteractiveViewer` failing to render when `alignment` is set ([#6744](https://github.com/flet-dev/flet/issues/6744), [#6887](https://github.com/flet-dev/flet/pull/6887)) by @ndonkoHenri.
 * flet-charts: Fix `ScatterChart` failing to render when a `ScatterChartSpot` has `x_error` or `y_error` set. Error ranges are now set with the new `ChartErrorRange` type and drawn as error bars in the color of their spot ([#6885](https://github.com/flet-dev/flet/pull/6885)) by @ndonkoHenri.
 * Fix iOS apps that use `sqlite3` stopping with `Assertion failed: (0), function isBulkReadStatement` when run from Xcode on iOS 18 and later, by turning off Xcode's Thread Performance Checker in the scheme generated by `flet build` ([#5480](https://github.com/flet-dev/flet/issues/5480), [#6882](https://github.com/flet-dev/flet/pull/6882)) by @ndonkoHenri.

sdk/python/packages/flet-cli/src/flet_cli/utils/android_sdk.py

@@ -13,12 +13,15 @@
 ANDROID_CMDLINE_TOOLS_VERSION = "12.0"
 
 MINIMAL_PACKAGES = [
-    "cmdline-tools;latest",
     "platform-tools",
     "platforms;android-35",
     "build-tools;34.0.0",
 ]
 
+# Written to the standard input of `sdkmanager`, which reads one answer line per
+# license prompt; `--licenses` also asks once before showing the licenses.
+SDKMANAGER_ANSWERS = "y\n" * 50
+
 
 class AndroidSDK:
     """
@@ -103,6 +106,11 @@ def cmdline_tools_bin(self, home_dir: Path) -> Optional[Path]:
         """
         Return the `cmdline-tools` binary directory in an SDK installation.
 
+        The version installed by this CLI is preferred over `latest`, because
+        from version 23.0, `sdkmanager` is a wrapper around the Android CLI,
+        which ignores `--licenses`, collects usage metrics by default and fails
+        on Windows.
+
         Args:
             home_dir: Android SDK home directory.
 
@@ -111,8 +119,8 @@ def cmdline_tools_bin(self, home_dir: Path) -> Optional[Path]:
         """
 
         for d in [
-            home_dir / "cmdline-tools" / "latest" / "bin",
             home_dir / "cmdline-tools" / ANDROID_CMDLINE_TOOLS_VERSION / "bin",
+            home_dir / "cmdline-tools" / "latest" / "bin",
         ]:
             if d.exists():
                 return d
@@ -322,36 +330,23 @@ def _install_package(self, home_dir: Path, package_name: str) -> int:
             RuntimeError: If package installation fails.
         """
 
-        if home_dir.joinpath(*package_name.split(";")).exists():
+        package_dir = home_dir.joinpath(*package_name.split(";"))
+        if package_dir.exists():
             self.log(f'Android SDK package "{package_name}" is already installed')
             return 0
 
         self.log(f'Installing Android SDK package "{package_name}"')
 
         p = self.run(
-            (
-                [
-                    "sh",
-                    "-c",
-                    f'yes | "{self.sdkmanager_exe(home_dir)}" "{package_name}"',
-                ]
-                if platform.system() != "Windows"
-                else [
-                    "cmd.exe",
-                    "/C",
-                    "echo",
-                    "y",
-                    "|",
-                    self.sdkmanager_exe(home_dir),
-                    package_name,
-                ]
-            ),
+            [self.sdkmanager_exe(home_dir), package_name],
             env={"ANDROID_HOME": str(home_dir)},
             capture_output=False,
+            input=SDKMANAGER_ANSWERS,
         )
-        if p.returncode != 0:
+        # sdkmanager exits with 0 when it skips a package whose license is declined
+        if p.returncode != 0 or not package_dir.exists():
             self.log(p.stderr)
-            raise RuntimeError("Error installing Android SDK tools")
+            raise RuntimeError(f'Error installing Android SDK package "{package_name}"')
         return 1
 
     def _accept_licenses(self, home_dir: Path):
@@ -368,23 +363,14 @@ def _accept_licenses(self, home_dir: Path):
         self.log("Accepting Android SDK licenses")
 
         p = self.run(
-            (
-                ["sh", "-c", f'yes | "{self.sdkmanager_exe(home_dir)}" --licenses']
-                if platform.system() != "Windows"
-                else [
-                    "cmd.exe",
-                    "/C",
-                    "echo",
-                    "y",
-                    "|",
-                    self.sdkmanager_exe(home_dir),
-                    "--licenses",
-                ]
-            ),
+            [self.sdkmanager_exe(home_dir), "--licenses"],
             env={"ANDROID_HOME": str(home_dir)},
             capture_output=False,
+            input=SDKMANAGER_ANSWERS,
         )
-        if p.returncode != 0:
+        # sdkmanager exits with 0 when licenses are declined
+        license_file = home_dir / "licenses" / "android-sdk-license"
+        if p.returncode != 0 or not license_file.exists():
             self.log(p.stderr)
             raise RuntimeError("Error accepting Android SDK licenses")
 
@@ -415,7 +401,7 @@ def get_installed_packages(self, home_dir: Path):
             )
         return p.stdout
 
-    def run(self, args, env=None, cwd=None, capture_output=True):
+    def run(self, args, env=None, cwd=None, capture_output=True, input=None):
         """
         Run a subprocess configured for Android SDK tooling.
 
@@ -427,6 +413,8 @@ def run(self, args, env=None, cwd=None, capture_output=True):
             env: Optional additional environment variables.
             cwd: Optional working directory. Defaults to current directory.
             capture_output: Forwarded to subprocess helper.
+            input: Optional text for the subprocess's standard input. Forwarded
+                to subprocess helper.
 
         Returns:
             Subprocess result object returned by `flet_cli.utils.processes.run`.
@@ -447,4 +435,5 @@ def run(self, args, env=None, cwd=None, capture_output=True):
             env=cmd_env,
             capture_output=capture_output,
             log=self.log,
+            input=input,
         )

sdk/python/packages/flet-cli/src/flet_cli/utils/processes.py

@@ -1,3 +1,4 @@
+import contextlib
 import os
 import subprocess
 from typing import Optional
@@ -8,7 +9,14 @@
     from ctypes import windll
 
 
-def run(args, cwd, env: Optional[dict] = None, capture_output=True, log=None):
+def run(
+    args,
+    cwd,
+    env: Optional[dict] = None,
+    capture_output=True,
+    log=None,
+    input: Optional[str] = None,
+):
     """
     Execute a subprocess command with optional streamed logging.
 
@@ -22,6 +30,9 @@ def run(args, cwd, env: Optional[dict] = None, capture_output=True, log=None):
         capture_output: If `True`, run with `subprocess.run` and
             capture output in memory. If `False`, stream combined output line by line.
         log: Optional callback receiving each output line when `capture_output=False`.
+        input: Optional text written to the command's standard input, which is
+            then closed. When `capture_output=False`, it is written before any
+            output is read, so it must fit in the OS pipe buffer.
 
     Returns:
         A completed `subprocess.CompletedProcess`
@@ -49,6 +60,7 @@ def run(args, cwd, env: Optional[dict] = None, capture_output=True, log=None):
         process = subprocess.run(
             args,
             cwd=cwd,
+            input=input,
             capture_output=True,
             text=True,
             encoding="utf-8",
@@ -68,6 +80,12 @@ def run(args, cwd, env: Optional[dict] = None, capture_output=True, log=None):
             errors="replace",
         )
 
+        if input is not None:
+            # The process may exit or close its standard input before reading it all
+            with contextlib.suppress(OSError):
+                process.stdin.write(input)
+                process.stdin.close()
+
         try:
             while True:
                 stdout_line = process.stdout.readline()