Hessian calc hangs

I’m using psi4 1.2.1 on a Linux Fedora 25 machine. The following input hangs in the calculation of the DFJK gradients:

memory 3 gb
molecule {
 0 1
B2 S1  1.35
S3 B2  1.45  S1  120.
B4 S3  1.45  B2  120.  S1  180.
S5 B4  1.35  S3  120.  B2  180.

set basis sto-3g

The job hangs in DFJKGrad:

  ==> DFJKGrad: Density-Fitted SCF Gradients <==

    Gradient:                    2
    J tasked:                  Yes
    K tasked:                  Yes
    wK tasked:                  No
    OpenMP threads:              1
    Integrals threads:           1
    Memory (MB):              2145
    Schwarz Cutoff:          0E+00
    Fitting Condition:       1E-12

   => Auxiliary Basis Set <=

  Basis Set: (STO-3G AUX)
    Blend: DEF2-SVP-JKFIT
    Number of shells: 164
    Number of basis function: 534
    Number of Cartesian functions: 643
    Spherical Harmonics?: true
    Max angular momentum: 4

The next line ought to be about memory allocation, something like this:

DFHelper Memory: AOs need 0.001 [GiB]; user supplied 2.515 [GiB]. Using in-core AOs.

The job will run if I add

scf_type direct

So perhaps something is wrong with the algorithm that tries to determine the memory for density-fitted JK gradients.