Crash on iOS 7.1

在Storyboard的一个Controller里添加了FDStackView，用代码dismiss该controller时崩溃在FDStackViewDistributionLayoutArrangement.m第226行：[self.canvas removeConstraints:self.relatedDimensionConstraints.fd_allObjects];
控制台输出：
Objective: {objective 0x178839a40: <999:-18.4039, 998:-342.146, 997:25.7032, 996:-0.509864, 750:826, 251:789, 25:1248> + <750:1, 251:1>_0x1708ad740.negError{id: 1554} + <750:1, 251:1>_0x1708ad7a0.negError{id: 1558} + <750:1, 251:1>_0x1708ad800.negError{id: 1560} + <750:1, 251:1>_0x1708ad8c0.posErrorMarker{id: 1561} + <750:1, 251:1>_0x1708ad920.posErrorMarker{id: 1563} + 750:1_0x1708ad980.negError{id: 1574} + <750:-6.44498e-07, 251:1>_0x1708ad980.posErrorMarker{id: 1573} + <750:1, 25:-2>_0x1708ad9e0.negError{id: 1576} + <251:1, 25:2>_0x1708ad9e0.posErrorMarker{id: 1575} + <750:1, 251:1>_0x1708adb60.negError{id: 1632} + <750:1, 251:1>_0x1708adbc0.negError{id: 1634} + <750:1, 251:1>_0x1708adc20.negError{id: 1636} + <750:1, 251:1>_0x1708adc80.negError{id: 1638} + <750:-2, 251:4>_0x171280320.marker{id: 1262} + <750:-2, 251:4>_0x171280780.marker{id: 1274} + 251:1_0x17128c990.marker{id: 1470} + 51:2_0x17128d3e0:FDSV-spanning-fit.negError{id: 1387} + 999.5:2_0x17128d430:FDSV-spanning-boundary.posErrorMarker{id: 1389} + 999.5:1_0x17128d480:FDSV-spanning-boundary.error{id: 1394} + 999.5:1_0x17128d4d0:FDSV-spanning-boundary.negError{id: 1397} + 999.5:1_0x17128d4d0:FDSV-spanning-boundary.posErrorMarker{id: 1396} + 999.5:1_0x17128d520:FDSV-spanning-boundary.error{id: 1400} + 999.5:2_0x17128d570:FDSV-spanning-boundary.negError{id: 1402} + 999.5:1_0x17128d5c0:FDSV-spanning-boundary.error{id: 1405} + 251:1_0x17128d610.marker{id: 1316} + 999.5:2_0x17128d660:FDSV-spanning-boundary.posErrorMarker{id: 1406} + 251:1_0x17128d930.marker{id: 1318} + 750:-1_0x17128db60.marker{id: 1320} + 251:-1_0x17128dc50.marker{id: 1428} + 251:-1_0x17128dcf0.marker{id: 1434} + 251:-1_0x17128dd90.marker{id: 1439} + 251:-1_0x17128dde0.marker{id: 1441} + 750:0_0x17128de80.marker{id: 1445} + 750:0_0x17128ded0.marker{id: 1447} + 750:1_0x17128df20.marker{id: 1450} + 750:1_0x17128dfc0.marker{id: 1455} + 251:1_0x17128e1f0.marker{id: 1474} + 251:1_0x17128e240.marker{id: 1476} + <750:1, 251:-2>_0x17128e2e0.marker{id: 1478} + <750:1, 251:-2>_0x17128e330.marker{id: 1481} + 750:0_0x1712940a0:FDSV-fill-proportionally.negError{id: 1606} + 750:0_0x171294280:FDSV-fill-proportionally.negError{id: 1610} + 25:2_0x1712946e0:FDSV-ambiguity-suppression.negError{id: 1620} + 25:2_0x1712948c0:FDSV-ambiguity-suppression.negError{id: 1623} + 999.5:1_0x1712949b0:FDSV-alignment.marker{id: 1624} + 25:2_0x171294aa0:FDSV-ambiguity-suppression.negError{id: 1626} + 999.5:-1_0x171294b90:FDSV-alignment.marker{id: 1627} + 25:2_0x171294c80:FDSV-ambiguity-suppression.negError{id: 1629} + 999.5:1_0x171294d70:FDSV-alignment.marker{id: 1630} + <750:-1, 251:2>_0x178a86f90.marker{id: 112} + 999:2_0x178aab760.negError{id: 1507} + 999:2_0x178aab7c0.negError{id: 1510} + <750:1, 251:1>_0x178aac6c0.negError{id: 1556} + 750:1_0x178aac720.negError{id: 1566} + 250:1_0x178aac720.posErrorMarker{id: 1565} + 750:1_0x178aac780.negError{id: 1568} + 250:1_0x178aac780.posErrorMarker{id: 1567} + 750:1_0x178aac8a0.negError{id: 1578} + 250:1_0x178aac8a0.posErrorMarker{id: 1577} + 750:1_0x178aac900.negError{id: 1580} + 250:1_0x178aac900.posErrorMarker{id: 1579} + 750:1_0x178aac960.negError{id: 1582} + 251:1_0x178aac960.posErrorMarker{id: 1581} + <750:1, 25:-2>_0x178aac9c0.negError{id: 1584} + <251:1, 25:2>_0x178aac9c0.posErrorMarker{id: 1583} + 750:1_0x178aaca20.negError{id: 1586} + <750:0, 251:1>_0x178aaca20.posErrorMarker{id: 1585} + <750:1, 25:-2>_0x178aaca80.negError{id: 1588} + <251:1, 25:2>_0x178aaca80.posErrorMarker{id: 1587} + 750:1_0x178aacae0.negError{id: 1590} + 250:1_0x178aacae0.posErrorMarker{id: 1589} + 750:1_0x178aacb40.negError{id: 1592} + 250:1_0x178aacb40.posErrorMarker{id: 1591} + 750:1_0x178aacba0.negError{id: 1594} + <750:0, 251:1>_0x178aacba0.posErrorMarker{id: 1593} + <750:1, 25:-2>_0x178aacc00.negError{id: 1596} + <251:1, 25:2>_0x178aacc00.posErrorMarker{id: 1595} + <750:-2, 251:4>_0x179283020.marker{id: 1305} + 251:1_0x179289650.marker{id: 1473} + 999.5:1_0x179289dd0:FDSV-spanning-boundary.error{id: 1410} + 999.5:2_0x179289e20:FDSV-spanning-boundary.negError{id: 1412} + 999.5:1_0x179289e70:FDSV-spanning-boundary.error{id: 1415} + 25:2_0x179289fb0:FDSV-ambiguity-suppression.negError{id: 1337} + 25:2_0x17928a050:FDSV-ambiguity-suppression.negError{id: 1340} + 25:2_0x17928a0f0:FDSV-ambiguity-suppression.negError{id: 1350} + 25:2_0x17928a190:FDSV-ambiguity-suppression.negError{id: 1353} + <750:-1, 251:2>_0x17928a5a0.marker{id: 1519} + 750:0_0x179290680:FDSV-canvas-connection.marker{id: 1597} + 750:0_0x1792906d0.marker{id: 1598} + <750:-2, 251:4>_0x1792920c0.marker{id: 1688} + 750:0_{id: 148} + 750:0_{id: 179} + 750:0_{id: 186} + 750:6.37025e-07_{id: 187} + 750:0_{id: 420} + 750:0_{id: 424} + 51:1_FDLayoutSpacer:0x178588470.Width{id: 1388} + 750:0_UIImageView:0x1703eb600.Width{id: 1334} + 750:0_UIImageView:0x1703eba00.minX{id: 1370} + 750:0_UIImageView:0x1783ecc00.minX{id: 1372} + 750:0_UIImageView:0x1783ecf00.minX{id: 1375} + 999:1__UILayoutGuide:0x178588540.Width{id: 1508} + 999:1*_UILayoutGuide:0x178588610.Width{id: 1511}}

Start with FDStackViewDistributionLayoutArrangement.m at line 226 and reproduce the reported case: an FDStackView added in a storyboard controller that is dismissed in code on iOS 7.1. Inspect the constraint-removal path and use the supplied console output to identify why the crash occurs. Done means dismissing the controller no longer crashes on the reported configuration.

Written by the indexing model from the issue text.