test() does not capture all output in test 1696

The following output can be observed when testing on Windows (and not on linux, at least pipeline I am checking).

Running test id 1696      omp_get_max_threads() = 20
omp_get_thread_limit() = 2147483647
DTthreads = 2
No list columns are present. Setting sep2='' otherwise quote='auto' would quote fields containing sep2.
Column writers: 5 5 5 5 5 5 5 
maxLineLen=56 from sample. Found in 0.000s
Writing column names ... done in 0.000s
Writing 1 rows in 1 batches of 1 rows (each buffer size 8MB, showProgress=0, nth=1) ... done (actual nth=1, anyBufferGrown=no, maxBuffUsed=0%)

Test 1696 checks output of a call but AFAIU it should capture all the output and compare against it.

# test for #1819, verbose message for bmerge
old_opt = getOption("datatable.verbose")
options(datatable.verbose = TRUE)
x = data.table(A = 10:17)
test(1696.0, x[A %inrange% 13:14], output="bmerge")
# restore verbosity
options(datatable.verbose = old_opt)

Test pass. The only problem is polluted log output in main.Rout.

Rdatatable / data.table

test() does not capture all output in test 1696 #2867