The Scala Team is very happy to announce a new stable release of the Scala distribution: Scala 2.9.1 final [1] is currently available from our Download Page [1]. Many thanks to all our contributors and testers! This is a maintenance release: several bugs have been fixed, and other improvements introduced. The new Scala 2.9.1 release has been designed to be fully binary compatible with the previous version 2.9.0.1.

The Scala 2.9.1 distribution

What is new?

The 2.9.1 release of Scala includes many bug fixes and improvements, in particular to the interpreter: most of the interpreter changes available in the development mainline have been ported to the 2.9.x release branch.

This releases fixes the following issues:

Ticket	Summary
SI-1048 [2]	Assertion error in wild mix of pattern matching and existentials [2]
SI-3501 [3]	java.lang.Error: no-symbol does not have owner with CPS-Plugin [3]
SI-4237 [4]	Syntactic sugar for calling mutator doesn't always work [4]
SI-4547 [5]	Failure of implicit conversion from {int, long, double} to {BigInt, BigDecimal} [5]
SI-4556 [6]	:type - no error details [6]
SI-4588 [7]	Scattered method parameter list with default argument [7]
SI-4593 [8]	typechecker throws NoSuchElementException: key not found: trait Nothing [8]
SI-4603 [9]	Unable to inherit from Hadoop Mapper (new or old API) in 2.9.0 with code that functions in 2.8.1 [9]
SI-4614 [10]	scala REPL not launching on trunk builds [10]
SI-4659 [11]	Change BigInt.~ to BigInt.unary_~ [11]
SI-4660 [12]	GroupBy in views returns wrong result in 2.9.x [12]
SI-4662 [13]	Regression: Source.getLines broken in 2.9.0.1 [13]
SI-4671 [14]	scala.io.Source scala2.9 REPL wrong result when dividing into two lines [14]
SI-4678 [15]	flatMap is broken for parallel collections in 2.9.0 & 2.9.0-1 [15]
SI-4692 [16]	Implicit lookup failure for type alias [16]
SI-4705 [17]	Interpreter blocks on ctrl-d (OS X, at least) [17]
SI-4712 [18]	Raw type used in argument position is not existentially quantified [18]
SI-4748 [19]	Unexpected return value for Range(x,y).init [19]
SI-4752 [20]	Hash code for None changes across JVM invocations [20]
SI-4757 [21]	Nonexisting symbol error with separate compilation [21]
SI-4759 [22]	Actors: java.lang.RuntimeException: unhandled timeout exception when using '!?' [22]
SI-4782 [23]	scalac ignores empty classpath argument [23]
SI-4791 [24]	Unnecessary structural type in collection.Iterator's implementation [24]
SI-4821 [25]	++= in ArrayBuffer is optimized only for collection.mutable.IndexedSeq and not for all IndexedSeqs [25]

The complete list of all the changes (bug fixes and improvements) is available here:

24909 [26], 24919 [27], 24941 [28], 24961 [29], 24963 [30], 24965 [31], 24981 [32], 24984 [33], 24986 [34], 24987 [35], 24992 [36], 24993 [37], 24999 [38], 25000 [39], 25001 [40], 25002 [41], 25003 [42], 25004 [43], 25005 [44], 25006 [45], 25007 [46], 25008 [47], 25009 [48], 25010 [49], 25015 [50], 25028 [51], 25029 [52], 25030 [53], 25031 [54], 25033 [55], 25038 [56], 25039 [57], 25040 [58], 25041 [59], 25044 [60], 25045 [61], 25046 [62], 25048 [63], 25050 [64], 25051 [65], 25052 [66], 25053 [67], 25054 [68], 25055 [69], 25057 [70], 25058 [71], 25059 [72], 25061 [73], 25062 [74], 25063 [75], 25065 [76], 25066 [77], 25069 [78], 25068 [79], 25070 [80], 25071 [81], 25072 [82], 25074 [83], 25075 [84], 25076 [85], 25080 [86], 25081 [87], 25082 [88], 25083 [89], 25085 [90], 25087 [91], 25088 [92], 25090 [93], 25091 [94], 25092 [95], 25093 [96], 25094 [97], 25095 [98], 25096 [99], 25097 [100], 25099 [101], 25100 [102], 25101 [103], 25110 [104], 25111 [105], 25112 [106], 25113 [107], 25114 [108], 25117 [109], 25119 [110], 25122 [111], 25124 [112], 25125 [113], 25126 [114], 25127 [115], 25128 [116], 25130 [117], 25132 [118], 25133 [119], 25134 [120], 25135 [121], 25136 [122], 25137 [123], 25138 [124], 25138 [124], 25139 [125], 25140 [126], 25141 [127], 25142 [128], 25144 [129], 25145 [130], 25146 [131], 25148 [132], 25149 [133], 25152 [134], 25153 [135], 25158 [136], 25160 [137], 25161 [138], 25162 [139], 25164 [140], 25167 [141], 25169 [142], 25170 [143], 25171 [144], 25172 [145], 25202 [146], 25204 [147], 25207 [148], 25208 [149], 25209 [150], 25212 [151], 25252 [152], 25374 [153], 25375 [154], 25377 [155], 25379 [156], 25380 [157], 25381 [158], 25384 [159], 25385 [160], 25390 [161], 25404 [162], 25405 [163], 25462 [164], 25504 [165], 25506 [166], 25509 [167], 25531 [168], 25534 [169], 25544 [170], 25548 [171], 25549 [172].

Note: the interpreter option '-i' may behave incorrectly in this version. In case you require it, please just add the option '-Yrepl-sync' to your command line as well.

Links:
[1] http://www.scala-lang.org/downloads#
[2] https://issues.scala-lang.org/browse/SI-1048
[3] https://issues.scala-lang.org/browse/SI-3501
[4] https://issues.scala-lang.org/browse/SI-4237
[5] https://issues.scala-lang.org/browse/SI-4547
[6] https://issues.scala-lang.org/browse/SI-4556
[7] https://issues.scala-lang.org/browse/SI-4588
[8] https://issues.scala-lang.org/browse/SI-4593
[9] https://issues.scala-lang.org/browse/SI-4603
[10] https://issues.scala-lang.org/browse/SI-4614
[11] https://issues.scala-lang.org/browse/SI-4659
[12] https://issues.scala-lang.org/browse/SI-4660
[13] https://issues.scala-lang.org/browse/SI-4662
[14] https://issues.scala-lang.org/browse/SI-4671
[15] https://issues.scala-lang.org/browse/SI-4678
[16] https://issues.scala-lang.org/browse/SI-4692
[17] https://issues.scala-lang.org/browse/SI-4705
[18] https://issues.scala-lang.org/browse/SI-4712
[19] https://issues.scala-lang.org/browse/SI-4748
[20] https://issues.scala-lang.org/browse/SI-4752
[21] https://issues.scala-lang.org/browse/SI-4757
[22] https://issues.scala-lang.org/browse/SI-4759
[23] https://issues.scala-lang.org/browse/SI-4782
[24] https://issues.scala-lang.org/browse/SI-4791
[25] https://issues.scala-lang.org/browse/SI-4821
[26] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24909
[27] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24919
[28] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24941
[29] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24961
[30] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24963
[31] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24965
[32] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24981
[33] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24984
[34] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24986
[35] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24987
[36] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24992
[37] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24993
[38] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=24999
[39] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25000
[40] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25001
[41] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25002
[42] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25003
[43] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25004
[44] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25005
[45] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25006
[46] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25007
[47] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25008
[48] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25009
[49] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25010
[50] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25015
[51] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25028
[52] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25029
[53] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25030
[54] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25031
[55] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25033
[56] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25038
[57] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25039
[58] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25040
[59] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25041
[60] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25044
[61] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25045
[62] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25046
[63] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25048
[64] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25050
[65] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25051
[66] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25052
[67] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25053
[68] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25054
[69] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25055
[70] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25057
[71] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25058
[72] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25059
[73] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25061
[74] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25062
[75] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25063
[76] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25065
[77] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25066
[78] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25069
[79] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25068
[80] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25070
[81] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25071
[82] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25072
[83] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25074
[84] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25075
[85] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25076
[86] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25080
[87] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25081
[88] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25082
[89] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25083
[90] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25085
[91] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25087
[92] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25088
[93] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25090
[94] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25091
[95] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25092
[96] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25093
[97] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25094
[98] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25095
[99] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25096
[100] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25097
[101] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25099
[102] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25100
[103] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25101
[104] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25110
[105] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25111
[106] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25112
[107] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25113
[108] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25114
[109] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25117
[110] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25119
[111] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25122
[112] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25124
[113] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25125
[114] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25126
[115] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25127
[116] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25128
[117] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25130
[118] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25132
[119] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25133
[120] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25134
[121] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25135
[122] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25136
[123] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25137
[124] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25138
[125] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25139
[126] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25140
[127] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25141
[128] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25142
[129] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25144
[130] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25145
[131] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25146
[132] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25148
[133] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25149
[134] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25152
[135] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25153
[136] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25158
[137] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25160
[138] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25161
[139] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25162
[140] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25164
[141] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25167
[142] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25169
[143] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25170
[144] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25171
[145] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25172
[146] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25202
[147] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25204
[148] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25207
[149] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25208
[150] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25209
[151] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25212
[152] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25252
[153] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25374
[154] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25375
[155] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25377
[156] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25379
[157] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25380
[158] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25381
[159] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25384
[160] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25385
[161] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25390
[162] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25404
[163] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25405
[164] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25462
[165] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25504
[166] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25506
[167] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25509
[168] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25531
[169] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25534
[170] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25544
[171] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25548
[172] https://codereview.scala-lang.org/fisheye/changelog/scala-svn?cs=25549