match => prompt only at the beginning of the line

some commands print strings resembling the prompt, e.g.:
=> crc32 0x48000000 0xc8438; echo $?
crc32 for 48000000 ... 480c8437 ==> bd70c7dc

Author: michalskrivanek

packages/jumpstarter-driver-uboot/jumpstarter_driver_uboot/client.py

@@ -46,7 +46,9 @@ def reboot_to_console(self, *, debug=False) -> Generator[None]:
             for _ in range(100):  # TODO: configurable retries
                 try:
                     p.send(ESC)
-                    p.expect_exact(self.prompt, timeout=0.1)
+                    # in case of "bootmenu" there are all sort of escape sequences in the output so try to
+                    # catch prompt without any leading newlines, hoping it's not in the menu text somewhere
+                    p.expect_exact(self.prompt.lstrip("\n"), timeout=0.1)
                 except pexpect.TIMEOUT:
                     continue
 

packages/jumpstarter-driver-uboot/jumpstarter_driver_uboot/driver.py

@@ -5,7 +5,7 @@
 
 @dataclass(kw_only=True)
 class UbootConsole(Driver):
-    prompt: str = "=>"
+    prompt: str = "\n=>"
 
     @classmethod
     def client(cls) -> str: