ptek ~/hello> bench .stack-work/install/x86_64-linux/*/*/bin/hello
benchmarking bench/.stack-work/install/x86_64-linux/ghc-7.10.3/7.10.3/bin/hello
time                 1.099 ms   (1.092 ms .. 1.107 ms)
                     1.000 R²   (0.999 R² .. 1.000 R²)
mean                 1.106 ms   (1.100 ms .. 1.112 ms)
std dev              20.16 μs   (15.32 μs .. 29.03 μs)

benchmarking bench/.stack-work/install/x86_64-linux/ghc-8.0.2/8.0.2/bin/hello
time                 1.001 ms   (994.6 μs .. 1.008 ms)
                     0.999 R²   (0.998 R² .. 1.000 R²)
mean                 999.8 μs   (995.3 μs .. 1.007 ms)
std dev              18.92 μs   (11.83 μs .. 33.00 μs)

benchmarking bench/.stack-work/install/x86_64-linux/ghc-8.2.1/8.2.1/bin/hello
time                 985.9 μs   (975.9 μs .. 994.3 μs)
                     0.999 R²   (0.999 R² .. 1.000 R²)
mean                 993.0 μs   (987.5 μs .. 997.5 μs)
std dev              18.40 μs   (14.44 μs .. 24.60 μs)

ptek ~/hello> ls -lah .stack-work/install/x86_64-linux/*/*/bin/hello
-rwxr-xr-x 1 ptek staff 815K Oct 21 11:30 .stack-work/install/x86_64-linux/ghc-7.10.3/7.10.3/bin/hello
-rwxr-xr-x 1 ptek staff 829K Oct 21 11:30 .stack-work/install/x86_64-linux/ghc-8.0.2/8.0.2/bin/hello
-rwxr-xr-x 1 ptek staff 741K Oct 21 11:30 .stack-work/install/x86_64-linux/ghc-8.2.1/8.2.1/bin/hello