UnsatFun test case fails on HEAD with quick build flavour

When I run the UnsatFun test case with a quick-built HEAD (using commit 568d7279), I get the following error:

=====> UnsatFun(optasm) 1 of 1 [0, 0, 0]
cd "stranal/sigs/UnsatFun.run" &&  "/home/rgscott/Software/ghc/inplace/bin/ghc-stage2" -c UnsatFun.hs -dcore-lint -dstg-lint -dcmm-lint -no-user-package-db -rtsopts -fno-warn-missed-specialisations -fshow-warning-groups -fdiagnostics-color=never -fno-diagnostics-show-caret -Werror=compat -dno-debug-output  -ddump-str-signatures -ddump-cpr-signatures -O -fasm < 
Actual stderr output differs from expected:
diff -uw "stranal/sigs/UnsatFun.run/UnsatFun.stderr.normalised" "stranal/sigs/UnsatFun.run/UnsatFun.comp.stderr.normalised"< 
--- stranal/sigs/UnsatFun.run/UnsatFun.stderr.normalised        2020-05-15 18:03:12.462788851 -0400
+++ stranal/sigs/UnsatFun.run/UnsatFun.comp.stderr.normalised   2020-05-15 18:03:12.462788851 -0400
@@ -1,8 +1,8 @@
 
 ==================== Strictness signatures ====================
 UnsatFun.$trModule:
-UnsatFun.f: <B,1*U(U)><B,A>b
-UnsatFun.g: <B,1*U(U)>b
+UnsatFun.f: <S,1*U(U)><L,A>x
+UnsatFun.g: <S,1*U(U)>x
 UnsatFun.g': <L,1*U(U)>
 UnsatFun.g3: <L,U(U)>
 UnsatFun.h: <C(S),1*C1(U)>
@@ -25,8 +25,8 @@
 
 ==================== Strictness signatures ====================
 UnsatFun.$trModule:
-UnsatFun.f: <B,1*U(U)><B,A>b
-UnsatFun.g: <B,1*U(U)>b
+UnsatFun.f: <S,1*U(U)><L,A>x
+UnsatFun.g: <S,1*U(U)>x
 UnsatFun.g': <L,1*U(U)>
 UnsatFun.g3: <L,U(U)>
 UnsatFun.h: <C(S),1*C1(U)>
*** unexpected failure for UnsatFun(optasm)

Performance Metrics (test environment: local):


None collected.


Unexpected results from:
TEST="UnsatFun"

SUMMARY for test run started at Fri May 15 18:03:11 2020 
0:00:00.499436 spent to go through
       1 total tests, which gave rise to
       3 test cases, of which
       2 were skipped

       0 had missing libraries
       0 expected passes
       0 expected failures

       0 caused framework failures
       0 caused framework warnings
       0 unexpected passes
       1 unexpected failures
       0 unexpected stat failures
       0 fragile tests

Unexpected failures:
   stranal/sigs/UnsatFun.run  UnsatFun [stderr mismatch] (optasm)

I haven't seen this failure on CI, so I'm assuming that this is quick-specific.

cc @sgraf812