From @lizmat

lizmat m​: loop { last without index("a","foo") } # feels to me this shouldn't hang ?
camelia rakudo-moar b28604​: OUTPUT«(timeout)»
m​: loop { print "foo" without index("a","foo") } # feels to me this shouldn't hang ?
camelia rakudo-moar b28604​: OUTPUT«(timeout)foofoofoofoofoofoofoofoofoofo​ofoofoofoofoofoofoofoofoofoofoofoofoofoofoofo​ofoofoofoofoofoofoofoofoofoofoofoofoofoofoofo​ofoofoofoofoofoofoofoofoofoofoofoofoofoofoofo​ofoofoofoofoofoofoofoofoofoofoofoofoofoofoofo​ofoofoofoofoofoofoofoofoofoofoofoofoof…»
jnthn m​: say index("a","foo")
camelia rakudo-moar b28604​: OUTPUT«Nil␤»
jnthn m​: say index("a","foo").defined
camelia rakudo-moar b28604​: OUTPUT«False␤»
jnthn m​: say index("a","foo").DEFINITE
camelia rakudo-moar b28604​: OUTPUT«False␤»
jnthn Yeah, looks busted and I'm not sure why :)
lizmat m​: say ?index("a","foo")
camelia rakudo-moar b28604​: OUTPUT«False␤»
jnthn without should care about .defined fwiw
lizmat m​: loop { last not with index("a","foo") } # also odd?
camelia rakudo-moar b28604​: OUTPUT«===SORRY!=== Error while compiling <tmp>␤Undeclared routine​:␤ with used at line 1␤␤»
lizmat m​: FOO​: loop { last FOO without index("a","foo") } # this works
camelia rakudo-moar b28604​: ( no output )

From @zoffixznet

On Thu, 15 Dec 2016 03​:54​:40 -0800, elizabeth wrote​:

lizmat m​: loop { last without index("a","foo") } # feels to me this
shouldn't hang ?
camelia rakudo-moar b28604​: OUTPUT«(timeout)»
m​: loop { print "foo" without index("a","foo") } # feels to me this
shouldn't hang ?
camelia rakudo-moar b28604​:
OUTPUT«(timeout)foofoofoofoofoofoofoofoofoofo
ofoofoofoofoofoofoofoofoofoofoofoofoofoofoofo
ofoofoofoofoofoofoofoofoofoofoofoofoofoofoofo
ofoofoofoofoofoofoofoofoofoofoofoofoofoofoofo
ofoofoofoofoofoofoofoofoofoofoofoofoofoofoofo
ofoofoofoofoofoofoofoofoofoofoofoofoof…»
jnthn m​: say index("a","foo")
camelia rakudo-moar b28604​: OUTPUT«Nil␤»
jnthn m​: say index("a","foo").defined
camelia rakudo-moar b28604​: OUTPUT«False␤»
jnthn m​: say index("a","foo").DEFINITE
camelia rakudo-moar b28604​: OUTPUT«False␤»
jnthn Yeah, looks busted and I'm not sure why :)
lizmat m​: say ?index("a","foo")
camelia rakudo-moar b28604​: OUTPUT«False␤»
jnthn without should care about .defined fwiw
lizmat m​: loop { last not with index("a","foo") } # also odd?
camelia rakudo-moar b28604​: OUTPUT«===SORRY!=== Error while compiling
<tmp>␤Undeclared routine​:␤ with used at line 1␤␤»
lizmat m​: FOO​: loop { last FOO without index("a","foo") } # this
works
camelia rakudo-moar b28604​: ( no output )

Figured out the cause, working on a fix, which may... um... take a bit. It's tricky.

The RT System itself - Status changed from 'new' to 'open'

From @zoffixznet

On Thu, 15 Dec 2016 03​:54​:40 -0800, elizabeth wrote​:

lizmat m​: loop { last without index("a","foo") } # feels to me this
shouldn't hang ?
camelia rakudo-moar b28604​: OUTPUT«(timeout)»
m​: loop { print "foo" without index("a","foo") } # feels to me this
shouldn't hang ?
camelia rakudo-moar b28604​:
OUTPUT«(timeout)foofoofoofoofoofoofoofoofoofo
ofoofoofoofoofoofoofoofoofoofoofoofoofoofoofo
ofoofoofoofoofoofoofoofoofoofoofoofoofoofoofo
ofoofoofoofoofoofoofoofoofoofoofoofoofoofoofo
ofoofoofoofoofoofoofoofoofoofoofoofoofoofoofo
ofoofoofoofoofoofoofoofoofoofoofoofoof…»
jnthn m​: say index("a","foo")
camelia rakudo-moar b28604​: OUTPUT«Nil␤»
jnthn m​: say index("a","foo").defined
camelia rakudo-moar b28604​: OUTPUT«False␤»
jnthn m​: say index("a","foo").DEFINITE
camelia rakudo-moar b28604​: OUTPUT«False␤»
jnthn Yeah, looks busted and I'm not sure why :)
lizmat m​: say ?index("a","foo")
camelia rakudo-moar b28604​: OUTPUT«False␤»
jnthn without should care about .defined fwiw
lizmat m​: loop { last not with index("a","foo") } # also odd?
camelia rakudo-moar b28604​: OUTPUT«===SORRY!=== Error while compiling
<tmp>␤Undeclared routine​:␤ with used at line 1␤␤»
lizmat m​: FOO​: loop { last FOO without index("a","foo") } # this
works
camelia rakudo-moar b28604​: ( no output )

Thank you for the report. This is now fixed.

Fix​: rakudo/rakudo@9a3c35013e25f69
Tests​: Raku/roast@fc0d82adf5

@zoffixznet - Status changed from 'open' to 'resolved'