Bug#847288: libdbd-firebird-perl: FTBFS randomly (failing tests)

[Santiago Vila]

Ok, I made the following test today: Built this package 1000 times,
on 20 different autobuilders.

It built ok this many times in these autobuilders:

  67 uranio2
  58 uranio1
  53 e5
  53 e12
  48 leaseweb2
  48 leaseweb1
  47 e16
  35 e14
  34 e4
  34 e17
  34 e10
  32 e11
  30 e20
  28 e18

and it failed to build this many times in these autobuilders:

  65 e8
  65 e6
  64 e3
  61 e7
  52 yoda2
  50 yoda1
  50 skywalker1
   2 uranio2

Now the fun part: The machines on which it fails are the "fast" ones,
and the machines on which it builds ok are the "slow" ones.

I have good estimations for the CPU speed for these machines.

This is the "slowness" of the machines on which it fails to build:

e6                   0.413
e8                   0.413
e3                   0.417
e7                   0.417
yoda1                0.418
yoda2                0.429
skywalker1           0.446
uranio2              0.540

and this is the "slowness" of the machines on which it builds ok:

e12                  0.526
e5                   0.540
uranio2              0.540
e16                  0.646
uranio1              0.734
e14                  1.528
e17                  1.537
e10                  1.545
e11                  1.558
e4                   1.573
e18                  1.977
e20                  2.074

The "slowness" is the inverse of the speed. My unit of measure
(i.e. slowness 1) is the speed of my i3-3217U @ 1.80GHz at home,
which was my first autobuilder.

Can you host a virtual machine somewhere which is at least twice as
fast as my i3 at home? I guess, but I'm not sure, that the problem
could be reproduced there as well.

[ Of course, if we can confirm that speed is the issue here, this should
  be "serious" again, as packages should never fail to build just because
  the CPU is "too fast" ].

Thanks.