installcheck failing on psql_crosstab

Hi all,

With a low value of work_mem, like 1MB, I am noticing that the new
psql_crosstab is generating a couple of diffs with installcheck
(tested only on OSX 10.11):
***************
*** 127,134 ****  \crosstabview v h i  v  |   h0   | h1 | h2 | h4 | #null# ----+--------+----+----+----+--------
!  v1 | #null# |    | 3 +|    |
!     |        |    | 7  |    |  v2 |        | 3  |    |    |  v0 |        |    |    | 4 +| 5     |        |    |    |
-3|
 
--- 127,134 ----  \crosstabview v h i  v  |   h0   | h1 | h2 | h4 | #null# ----+--------+----+----+----+--------
!  v1 | #null# |    | 7 +|    |
!     |        |    | 3  |    |  v2 |        | 3  |    |    |  v0 |        |    |    | 4 +| 5     |        |    |    |
-3|
 
***************
*** 143,150 **** ----+------+-----+-----  h0 | baz  |     |  h1 |      | bar |
!  h2 | foo +|     |
!     | quux |     |  h4 |      |     | qux+     |      |     | dbl     |      |     | qux
--- 143,150 ---- ----+------+-----+-----  h0 | baz  |     |  h1 |      | bar |
!  h2 | quux+|     |
!     | foo  |     |  h4 |      |     | qux+     |      |     | dbl     |      |     | qux
***************
*** 156,163 ****  \crosstabview 1 "h" 4  v  | h0  | h1  |  h2  | h4  | ----+-----+-----+------+-----+-----
!  v1 | baz |     | foo +|     |
!     |     |     | quux |     |  v2 |     | bar |      |     |  v0 |     |     |      | qux+| qux     |     |     |
 | dbl |
 
--- 156,163 ----  \crosstabview 1 "h" 4  v  | h0  | h1  |  h2  | h4  | ----+-----+-----+------+-----+-----
!  v1 | baz |     | quux+|     |
!     |     |     | foo  |     |  v2 |     | bar |      |     |  v0 |     |     |      | qux+| qux     |     |     |
 | dbl |
 

======================================================================

I know that we guarantee that make installcheck may not work on many
target servers as a lot of tests are very GUC-sensitive, but this
looks a bit oversensitive to me, especially knowing that it is the
only diff generated by the whole test suite.
Don't you think that those tests could be made more portable?
Regards,
-- 
Michael