std.conv.to!string refuses to convert a char* to string.

[Venkat]

I am trying out the DJni library 
(https://github.com/Monnoroch/DJni). For some reason 
std.conv.to!string doesn't want to convert a char* to a 
string.The lines below are taken from the log. I see that the 
last frame is at gc_qalloc. I am not sure why it failed there. 
Can anybody elaborate on what is going on here ? Thanks in 
advance.

  91
  92
  93 Stack: [0x00007f749dfd9000,0x00007f749e0da000],  
sp=0x00007f749e0d8600,  free space=1021k
  94 Native frames: (J=compiled Java code, j=interpreted, Vv=VM 
code, C=native code)
  95 C  [libPrompt.so+0x6b0cc]  gc_qalloc+0x2c
  96 C  [libPrompt.so+0x7bf18]  
_D2rt8lifetime12__arrayAllocFNaNbmxC8TypeInfoxQlZS4core6memory8BlkInfo_+0xec
  97 C  [libPrompt.so+0x6c2fa]  _d_newarrayU+0x86
  98 C  [libPrompt.so+0x593a7]  
_D6object__T4_dupTxaTaZQlFNaNbAxaZAa+0x1f
  99 C  [libPrompt.so+0x59384]  
_D6object__T11_trustedDupTxaTaZQtFNaNbNeAxaZAa+0x20
100 C  [libPrompt.so+0x59360]  
_D6object__T3dupTaZQhFNaNbNdNfAxaZAa+0x20
101 C  [libPrompt.so+0x5932a]  
_D3std4conv__T6toImplTAyaTPxaZQqFQhZ9__lambda2MFNaNbZQBf+0x3e
102 C  [libPrompt.so+0x592ea]  
_D3std4conv__T6toImplTAyaTPxaZQqFNaNbQlZQs+0x16
103 C  [libPrompt.so+0x592d1]  
_D3std4conv__T2toTAyaZ__TQlTPxaZQsFNaNbQlZQy+0x9
104 C  [libPrompt.so+0x59289]  Java_Prompt_getLine+0x61
105 j  Prompt.getLine(Ljava/lang/String;)Ljava/lang/String;+0
106 j  Prompt.main([Ljava/lang/String;)V+11
107 v  ~StubRoutines::call_stub
108 V  [libjvm.so+0x690c66]  JavaCalls::call_helper(JavaValue*, 
methodHandle*, JavaCallArguments*, Thread*)+0x1056
109 V  [libjvm.so+0x6d2072]  jni_invoke_static(JNIEnv_*, 
JavaValue*, _jobject*, JNICallType, _jmethodID*, 
JNI_ArgumentPusher*, Thread*)+0x362
110 V  [libjvm.so+0x6ee8da]  jni_CallStaticVoidMethod+0x17a
111 C  [libjli.so+0x7bdf]  JavaMain+0x81f
112 C  [libpthread.so.0+0x8184]  start_thread+0xc4
113
114 Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
115 j  Prompt.getLine(Ljava/lang/String;)Ljava/lang/String;+0
116 j  Prompt.main([Ljava/lang/String;)V+11