| Message ID | 20240522154616.1265769-1-brandon.maier@collins.com |
|---|---|
| State | New |
| Headers | show |
| Series | support/testing/infra/emulator.py: fix qemu prompt detection | expand |
Hi Brandon, All, On 22/05/2024 17:46, Brandon Maier via buildroot wrote: > The qemu.run() method can break when a command happens to output the > string "# " to stdout. This is because qemu.run() detects when a > command > has completed by searching for the shell prompt, which by default is > "# ". It then captures everything before the "# " as the commands > output, causing the rest of output to be lost. > > To work around the issue set the prompt to something more unique. This > makes it less likely to appear in command output. I proposed a similar patch last year: https://patchwork.ozlabs.org/project/buildroot/list/?series=362761 Changing this prompt requires to also patch the "bash" runtime test, which is failing if the prompt is changed in the emulator. I think my patches were not included due to lost 3/4 and 4/4 patches in the series from my email provider. Those patches were originally in the v2. See: https://patchwork.ozlabs.org/project/buildroot/list/?series=359185&state=* > > Signed-off-by: Brandon Maier <brandon.maier@collins.com> > --- > support/testing/infra/emulator.py | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/support/testing/infra/emulator.py > b/support/testing/infra/emulator.py > index 624740fcb1..aa579443a6 100644 > --- a/support/testing/infra/emulator.py > +++ b/support/testing/infra/emulator.py > @@ -100,6 +100,13 @@ class Emulator(object): > index = self.qemu.expect(["# ", pexpect.TIMEOUT]) > if index != 0: > raise SystemError("Cannot login") > + > + # Set a prompt that is unlikely to appear in command output > + self.qemu.sendline("PS1='br-qemu-test# '") > + index = self.qemu.expect(["\r\nbr-qemu-test# ", > pexpect.TIMEOUT]) > + if index != 0: > + raise SystemError("Cannot set test prompt") > + > self.run("dmesg -n 1") > # Prevent the shell from wrapping the commands at 80 columns. > self.run("stty columns 29999") > @@ -110,13 +117,13 @@ class Emulator(object): > self.qemu.sendline(cmd) > if timeout != -1: > timeout *= self.timeout_multiplier > - self.qemu.expect("# ", timeout=timeout) > + self.qemu.expect("br-qemu-test# ", timeout=timeout) > # Remove double carriage return from qemu stdout so > str.splitlines() > # works as expected. > output = self.qemu.before.replace("\r\r", > "\r").splitlines()[1:] > > self.qemu.sendline("echo $?") > - self.qemu.expect("# ") > + self.qemu.expect("br-qemu-test# ") > exit_code = self.qemu.before.splitlines()[2] > exit_code = int(exit_code) > > -- > 2.45.1 > > _______________________________________________ > buildroot mailing list > buildroot@buildroot.org > https://lists.buildroot.org/mailman/listinfo/buildroot Best regards, Julien.
diff --git a/support/testing/infra/emulator.py b/support/testing/infra/emulator.py index 624740fcb1..aa579443a6 100644 --- a/support/testing/infra/emulator.py +++ b/support/testing/infra/emulator.py @@ -100,6 +100,13 @@ class Emulator(object): index = self.qemu.expect(["# ", pexpect.TIMEOUT]) if index != 0: raise SystemError("Cannot login") + + # Set a prompt that is unlikely to appear in command output + self.qemu.sendline("PS1='br-qemu-test# '") + index = self.qemu.expect(["\r\nbr-qemu-test# ", pexpect.TIMEOUT]) + if index != 0: + raise SystemError("Cannot set test prompt") + self.run("dmesg -n 1") # Prevent the shell from wrapping the commands at 80 columns. self.run("stty columns 29999") @@ -110,13 +117,13 @@ class Emulator(object): self.qemu.sendline(cmd) if timeout != -1: timeout *= self.timeout_multiplier - self.qemu.expect("# ", timeout=timeout) + self.qemu.expect("br-qemu-test# ", timeout=timeout) # Remove double carriage return from qemu stdout so str.splitlines() # works as expected. output = self.qemu.before.replace("\r\r", "\r").splitlines()[1:] self.qemu.sendline("echo $?") - self.qemu.expect("# ") + self.qemu.expect("br-qemu-test# ") exit_code = self.qemu.before.splitlines()[2] exit_code = int(exit_code)
The qemu.run() method can break when a command happens to output the string "# " to stdout. This is because qemu.run() detects when a command has completed by searching for the shell prompt, which by default is "# ". It then captures everything before the "# " as the commands output, causing the rest of output to be lost. To work around the issue set the prompt to something more unique. This makes it less likely to appear in command output. Signed-off-by: Brandon Maier <brandon.maier@collins.com> --- support/testing/infra/emulator.py | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)