nixos/tests/overlayfs: Fix erroneous backslashes

Since commit b7749c76715ba96727f7a12bc2514ddfa6847813, commands run as
part of VM tests are exiting immediately if an error happens.

When converting the overlayfs test to Python in commit
5ae92144ba04caefaf56b4204abe85b71dbb527b, the individual test commands
were crammed into one big string instead of using a series of test
commands like done in the Perl version.

Additionally, the backslash-escaped dollar signs were necessary in
Perl's double-quoted strings to avoid variable interpolation, for Python
however, this results in an actual backslash being inserted into the
command.

While this obviously results in an exit code of 1 (without an error
message, since it's using bash's expression evaluation command), the
test didn't fail because putting all these commands in one string will
result in only the last error code being relevant.

With the change to "set -e" for commands sent to test machines, this has
changed and with the exit code of all commands now relevant, the test
now fails because the errors from individual command substitutions that
were prevented by escaping the dollar sign are now actually visible.

This in turn also means that until now, we wouldn't have noticed if the
overlayfs test would have failed for real.

Signed-off-by: aszlig <aszlig@nix.build>

0 files changed, 0 insertions, 0 deletions