t/get.t fails (with newest Mojolicious?)

[eserte]

My smokers started to report test failures:

Can't use string ("ioloop") as a subroutine ref while "strict refs" in use at /home/cpansand/.cpan/build/2019051319/Mojolicious-8.15-5ZWr7g/blib/lib/Mojo/Promise.pm line 71.
# Tests were run but no plan was declared and done_testing() was not seen.
# Looks like your test exited with 255 just after 23.
t/get.t ................ 
Dubious, test returned 255 (wstat 65280, 0xff00)
All 23 subtests passed 

Statistical analysis suggests that this happens with the newest Mojolicious:

****************************************************************
Regression 'mod:Mojolicious'
****************************************************************
Name           	       Theta	      StdErr	 T-stat
[0='const']    	      1.0000	      0.0000	25115407236355660.00
[1='eq_8.02']  	      0.0000	      0.0000	   4.19
[2='eq_8.05']  	      0.0000	      0.0000	   1.42
[3='eq_8.07']  	      0.0000	      0.0000	   1.71
[4='eq_8.08']  	      0.0000	      0.0000	   1.42
[5='eq_8.09']  	      0.0000	      0.0000	   1.02
[6='eq_8.11']  	      0.0000	      0.0000	   0.81
[7='eq_8.12']  	      0.0000	      0.0000	   0.81
[8='eq_8.13']  	      0.0000	      0.0000	   2.28
[9='eq_8.14']  	      0.0000	      0.0000	   2.07
[10='eq_8.15'] 	     -1.0000	      0.0000	-18376405347026244.00

R^2= 1.000, N= 138, K= 11
****************************************************************

[Grinnz]

This is due to a breaking change in 8.15 which may be addressed by mojolicious/mojo#1348.