Fixup test for #10728

It was failing for WAY=ghci.

2 files changed, 8 insertions, 12 deletions

diff --git a/testsuite/tests/rts/T10728.hs b/testsuite/tests/rts/T10728.hs
index ff005faa63..a7c3d796f5 100644
--- a/testsuite/tests/rts/T10728.hs
+++ b/testsuite/tests/rts/T10728.hs
@@ -4,13 +4,13 @@ module Main where
 
 import GHC.Conc (getNumProcessors, getNumCapabilities)
 import GHC.Environment
-import Data.Char
+import Data.List
 
 main :: IO ()
 main = do
   -- We're parsing args passed in to make sure things are proper between the
   -- cli and the program.
-  n <- getN
+  n <- getN <$> getFullArgs
 
   c <- getNumCapabilities
   p <- getNumProcessors
@@ -30,11 +30,7 @@ check n c p
 check _n _c _p = "maxN Error"
 
 -- Parsing ``-maxN<n>`` from Args to be sure of it.
-getN :: IO Int
-getN = getFullArgs >>= return . go
-  where
-    go :: [String] -> Int
-    go as = case reads (
-      dropWhile (not . isDigit) . (!! 2) $ as ) :: [(Int, String)] of
-        [x] -> fst x
-        _ -> 0
+getN :: [String] -> Int
+getN args = case filter (isPrefixOf "-maxN") (reverse args) of
+    (maxN:_) -> read (drop 5 maxN)
+    _        -> error "Please pass `-maxN<n>` on command-line"
diff --git a/testsuite/tests/rts/all.T b/testsuite/tests/rts/all.T
index 951acbe4b3..5aa296a3b9 100644
--- a/testsuite/tests/rts/all.T
+++ b/testsuite/tests/rts/all.T
@@ -333,5 +333,5 @@ test('T10590', [ignore_output, when(opsys('mingw32'),skip)], compile_and_run, ['
 test('T10904', [ omit_ways(['ghci']), extra_run_opts('20000') ],
                compile_and_run, ['T10904lib.c'])
 
-test('T10728', [extra_run_opts('+RTS -maxN3 -RTS'), req_smp],
-           compile_and_run, ['-threaded'])
+test('T10728', [extra_run_opts('+RTS -maxN3 -RTS'), only_ways(['threaded2'])],
+               compile_and_run, [''])