diff --git a/tools/releasecreator/Pas2jsReleaseCreator.lpi b/tools/releasecreator/Pas2jsReleaseCreator.lpi
index 4e6f3c2..705fdc6 100644
--- a/tools/releasecreator/Pas2jsReleaseCreator.lpi
+++ b/tools/releasecreator/Pas2jsReleaseCreator.lpi
@@ -38,6 +38,11 @@
         <IsPartOfProject Value="True"/>
         <UnitName Value="FindWriteln"/>
       </Unit>
+      <Unit>
+        <Filename Value="prcutils.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="PRCUtils"/>
+      </Unit>
     </Units>
   </ProjectOptions>
   <CompilerOptions>
diff --git a/tools/releasecreator/Pas2jsReleaseCreator.lpr b/tools/releasecreator/Pas2jsReleaseCreator.lpr
index 1ffcb6b..6622351 100644
--- a/tools/releasecreator/Pas2jsReleaseCreator.lpr
+++ b/tools/releasecreator/Pas2jsReleaseCreator.lpr
@@ -8,8 +8,8 @@ uses
   {$IFDEF UNIX}
   cthreads,
   {$ENDIF}
-  LazUTF8, Classes, SysUtils, Types, CustApp, IniFiles, process, LazFileUtils,
-  FileUtil, FPCAdds, FindWriteln;
+  Classes, SysUtils, Types, CustApp, IniFiles, process,
+  FindWriteln, PRCUtils;
 
 const
   DefaultCfgFilename = 'pas2jsrelease.ini';
@@ -67,7 +67,6 @@ type
     function GetDefaultGit: string;
     function GetDefaultMake: string;
     function GetDefaultZip: string;
-    function GetLibExt(TargetOS: string = ''): string;
     function GetOption_String(ShortOption: char; const LongOption: string): string;
     function GetOption_Directory(ShortOption: char; const LongOption: string; const GetDefaultFunc: TGetDefaultEvent): string;
     function GetOption_Executable(ShortOption: char; const LongOption: string; const GetDefaultFunc: TGetDefaultEvent): string;
@@ -560,7 +559,7 @@ procedure TPas2jsReleaseCreator.CopySourceFolders;
       Log(etInfo,'Simulate: Copying folder "'+SrcDir+'" -> "'+DestDir+'"');
     end else begin
       Log(etInfo,'Copying folder "'+SrcDir+'" -> "'+DestDir+'"');
-      CopyDirTree(SrcDir,DestDir,[cffCreateDestDirectory,cffPreserveTime]);
+      CopyDirTree(SrcDir,DestDir,[cffCreateDestDirectory,cffPreserveTime,cffExceptionOnError]);
     end;
   end;
 
@@ -593,8 +592,7 @@ begin
     Log(etInfo,'Simulate: Copying "'+SrcFilename+'" -> "'+DestFilename+'"');
   end else begin
     Log(etInfo,'Copying "'+SrcFilename+'" -> "'+DestFilename+'"');
-    if not CopyFile(SrcFilename,DestFilename,[cffOverwriteFile,cffPreserveTime],false) then
-      Err('Unable to copy "'+SrcFilename+'" -> "'+DestFilename+'"');
+    CopyFile(SrcFilename,DestFilename,[cffOverwriteFile,cffPreserveTime,cffExceptionOnError]);
   end;
 end;
 
@@ -612,7 +610,7 @@ begin
   NeedBuild:=true;
   if not FileExists(ExeFilename) then
     log(etInfo,'Missing tool createconfig, building ...')
-  else if FileAge(SrcFilename)>FileAgeUTF8(ExeFilename) then
+  else if FileAge(SrcFilename)>FileAge(ExeFilename) then
     log(etInfo,'createconfig.pp changed, building ...')
   else
     NeedBuild:=false;
@@ -757,7 +755,7 @@ end;
 
 function TPas2jsReleaseCreator.GetDefaultBuildDir: string;
 begin
-  Result:=AppendPathDelim(ResolveDots(GetTempDir(false)));
+  Result:=AppendPathDelim(ExpandFileName(GetTempDir(false)));
 end;
 
 function TPas2jsReleaseCreator.GetDefaultTool(const Filename: string;
@@ -788,36 +786,6 @@ begin
   Result:=GetDefaultTool('zip'+GetExeExt,true);
 end;
 
-function TPas2jsReleaseCreator.GetLibExt(TargetOS: string): string;
-begin
-  if TargetOS='' then
-    TargetOS:=GetCompiledTargetOS;
-  TargetOS:=LowerCase(TargetOS);
-  if copy(TargetOS,1,3)='win' then
-    Result:='.dll'
-  else
-    case TargetOS of
-      'darwin',
-      'ios':
-         Result:='.dylib';
-      'linux',
-      'android',
-      'freebsd',
-      'openbsd',
-      'netbsd',
-      'dragonfly',
-      'haiku':
-         Result:='.so';
-      'browser',
-      'nodejs',
-      'electron',
-      'module':
-        Result:='.js';
-    else
-      Result:='';
-    end;
-end;
-
 function TPas2jsReleaseCreator.GetOption_String(ShortOption: char;
   const LongOption: string): string;
 begin
diff --git a/tools/releasecreator/prcutils.pas b/tools/releasecreator/prcutils.pas
new file mode 100644
index 0000000..1a40197
--- /dev/null
+++ b/tools/releasecreator/prcutils.pas
@@ -0,0 +1,488 @@
+unit PRCUtils;
+
+{$mode ObjFPC}{$H+}
+
+interface
+
+uses
+  {$IFDEF UNIX}
+  BaseUnix,
+  {$ENDIF}
+  Classes, SysUtils;
+
+function GetCompiledTargetOS: string;
+function GetCompiledTargetCPU: string;
+function GetExeExt: string;
+function GetLibExt(TargetOS: string = ''): string;
+
+function AppendPathDelim(const Path: string): string;
+function ChompPathDelim(const Path: string): string;
+function FilenameIsAbsolute(const TheFilename: string):boolean;
+function FileIsExecutable(const AFilename: string): boolean;
+function FileSize(const Filename: string): int64; overload;
+function FindDefaultExecutablePath(const Executable: string; const BaseDir: string = ''): string;
+
+// file search
+type
+  TSearchFileInPathFlag = (
+    sffDontSearchInBasePath, // do not search in BasePath, search only in SearchPath.
+    sffSearchLoUpCase,
+    sffFile, // must be file, not directory
+    sffExecutable, // file must be executable
+    sffDequoteSearchPath // ansi dequote
+    );
+  TSearchFileInPathFlags = set of TSearchFileInPathFlag;
+const
+  sffFindProgramInPath = [
+    {$IFDEF Unix}sffDontSearchInBasePath,{$ENDIF}
+    {$IFDEF Windows}sffDequoteSearchPath,{$ENDIF}
+    sffFile,
+    sffExecutable
+    ];
+
+function SearchFileInPath(const Filename, BasePath: string;
+  SearchPath: string; const Delimiter: string;
+  Flags: TSearchFileInPathFlags): string; overload;
+
+
+function ForceDirectory(DirectoryName: string): boolean;
+function DeleteDirectory(const DirectoryName: string; OnlyChildren: boolean): boolean;
+
+
+type
+  TCopyFileFlag = (
+    cffOverwriteFile,
+    cffCreateDestDirectory,
+    cffPreserveTime,
+    cffExceptionOnError
+    );
+  TCopyFileFlags = set of TCopyFileFlag;
+
+function CopyFile(const SrcFilename, DestFilename: string;
+                  Flags: TCopyFileFlags=[cffOverwriteFile]): boolean;
+function CopyDirTree(SrcDir, DestDir: string; Flags: TCopyFileFlags): boolean;
+
+implementation
+
+function GetCompiledTargetOS: string;
+begin
+  Result:=lowerCase({$I %FPCTARGETOS%});
+end;
+
+function GetCompiledTargetCPU: string;
+begin
+  Result:=lowerCase({$I %FPCTARGETCPU%});
+end;
+
+function GetExeExt: string;
+begin
+  {$IFDEF WINDOWS}
+  Result:='.exe';
+  {$ELSE}
+  Result:='';
+  {$ENDIF}
+end;
+
+function GetLibExt(TargetOS: string): string;
+begin
+  if TargetOS='' then
+    TargetOS:=GetCompiledTargetOS;
+  TargetOS:=LowerCase(TargetOS);
+  if copy(TargetOS,1,3)='win' then
+    Result:='.dll'
+  else
+    case TargetOS of
+      'darwin',
+      'ios':
+         Result:='.dylib';
+      'linux',
+      'android',
+      'freebsd',
+      'openbsd',
+      'netbsd',
+      'dragonfly',
+      'haiku':
+         Result:='.so';
+      'browser',
+      'nodejs',
+      'electron',
+      'module':
+        Result:='.js';
+    else
+      Result:='';
+    end;
+end;
+
+function AppendPathDelim(const Path: string): string;
+begin
+  if (Path<>'') and not (Path[length(Path)] in AllowDirectorySeparators) then
+    Result:=Path+PathDelim
+  else
+    Result:=Path;
+end;
+
+function ChompPathDelim(const Path: string): string;
+var
+  Len, MinLen: Integer;
+begin
+  Result:=Path;
+  if Path = '' then
+    exit;
+  Len:=length(Result);
+  if (Result[1] in AllowDirectorySeparators) then begin
+    MinLen := 1;
+    {$IFDEF HasUNCPaths}
+    if (Len >= 2) and (Result[2] in AllowDirectorySeparators) then
+      MinLen := 2; // keep UNC '\\', chomp 'a\' to 'a'
+    {$ENDIF}
+  end
+  else begin
+    MinLen := 0;
+    {$IFdef MSWindows}
+    if (Len >= 3) and (Result[1] in ['a'..'z', 'A'..'Z'])  and
+       (Result[2] = ':') and (Result[3] in AllowDirectorySeparators)
+    then
+      MinLen := 3;
+    {$ENDIF}
+  end;
+
+  while (Len > MinLen) and (Result[Len] in AllowDirectorySeparators) do dec(Len);
+  if Len<length(Result) then
+    SetLength(Result,Len);
+end;
+
+function FilenameIsAbsolute(const TheFilename: string):boolean;
+begin
+  {$IFDEF Unix}
+  Result:=(TheFilename<>'') and (TheFilename[1]='/');
+  {$ELSE}
+  Result:=((length(TheFilename)>=3) and
+           (TheFilename[1] in ['A'..'Z','a'..'z']) and (TheFilename[2]=':')  and (TheFilename[3]in AllowDirectorySeparators))
+      or ((length(TheFilename)>=2) and (TheFilename[1] in AllowDirectorySeparators) and (TheFilename[2] in AllowDirectorySeparators))
+      ;
+  {$ENDIF}
+end;
+
+function FileIsExecutable(const AFilename: string): boolean;
+{$IFDEF Unix}
+var
+  Info : Stat;
+{$ENDIF}
+begin
+  {$IFDEF Unix}
+  // first check AFilename is not a directory and then check if executable
+  Result:= (FpStat(AFilename,info{%H-})<>-1) and FPS_ISREG(info.st_mode) and
+           (BaseUnix.FpAccess(AFilename,BaseUnix.X_OK)=0);
+  {$ELSE}
+  Result:=FileExists(AFilename);
+  {$ENDIF}
+end;
+
+function FileSize(const Filename: string): int64;
+{$IFDEF Windows}
+var
+  R: TSearchRec;
+begin
+  if SysUtils.FindFirst(FileName, faAnyFile, R) = 0 then
+  begin
+    Result := R.Size;
+    SysUtils.FindClose(R);
+  end
+  else
+    Result := -1;
+end;
+{$ELSE}
+var
+  st: baseunix.stat;
+begin
+  if not fpstat(pointer(FileName),st{%H-})>=0 then
+    exit(-1);
+  Result := st.st_size;
+end;
+{$ENDIF}
+
+function FindDefaultExecutablePath(const Executable: string;
+  const BaseDir: string): string;
+var
+  Env: string;
+begin
+  if FilenameIsAbsolute(Executable) then begin
+    Result:=Executable;
+    if FileExists(Result) then exit;
+    {$IFDEF Windows}
+    if ExtractFileExt(Result)='' then begin
+      Result:=Result+'.exe';
+      if FileExists(Result) then exit;
+    end;
+    {$ENDIF}
+  end else begin
+    Env:=GetEnvironmentVariable('PATH');
+    Result:=SearchFileInPath(Executable, BaseDir, Env, PathSeparator, sffFindProgramInPath);
+    if Result<>'' then exit;
+    {$IFDEF Windows}
+    if ExtractFileExt(Executable)='' then begin
+      Result:=SearchFileInPath(Executable+'.exe', BaseDir, Env, PathSeparator, sffFindProgramInPath);
+      if Result<>'' then exit;
+    end;
+    {$ENDIF}
+  end;
+  Result:='';
+end;
+
+function SearchFileInPath(const Filename, BasePath: string; SearchPath: string;
+  const Delimiter: string; Flags: TSearchFileInPathFlags): string;
+var
+  p, StartPos, l, QuoteStart: integer;
+  CurPath, Base: string;
+begin
+  if (Filename='') then begin
+    Result:='';
+    exit;
+  end;
+  // check if filename absolute
+  if FilenameIsAbsolute(Filename) then begin
+    if FileExists(Filename) then begin
+      Result:=ExpandFilename(Filename);
+      exit;
+    end else begin
+      Result:='';
+      exit;
+    end;
+  end;
+  Base:=AppendPathDelim(ExpandFileName(BasePath));
+  // search in current directory
+  if (not (sffDontSearchInBasePath in Flags)) then begin
+    Result:=ExpandFilename(Base+Filename);
+    if FileExists(Result) then
+      exit;
+  end;
+  // search in search path
+  StartPos:=1;
+  l:=length(SearchPath);
+  while StartPos<=l do begin
+    p:=StartPos;
+    while (p<=l) and (pos(SearchPath[p],Delimiter)<1) do
+    begin
+      if (SearchPath[p]='"') and (sffDequoteSearchPath in Flags) then
+      begin
+        // For example: Windows allows set path=C:\"a;b c"\d;%path%
+        QuoteStart:=p;
+        repeat
+          inc(p);
+        until (p>l) or (SearchPath[p]='"');
+        if p<=l then
+        begin
+          system.delete(SearchPath,p,1);
+          system.delete(SearchPath,QuoteStart,1);
+          dec(l,2);
+          dec(p,2);
+        end;
+      end;
+      inc(p);
+    end;
+    CurPath:=copy(SearchPath,StartPos,p-StartPos);
+    CurPath:=ExpandFileName(CurPath);
+    StartPos:=p+1;
+    if CurPath='' then continue;
+    if not FilenameIsAbsolute(CurPath) then
+      CurPath:=Base+CurPath;
+    Result:=ExpandFilename(AppendPathDelim(CurPath)+Filename);
+    if not FileExists(Result) then
+      continue;
+    if (sffFile in Flags) and DirectoryExists(Result) then
+      continue;
+    if (sffExecutable in Flags) and not FileIsExecutable(Result) then
+      continue;
+    exit;
+  end;
+  Result:='';
+end;
+
+function ForceDirectory(DirectoryName: string): boolean;
+var
+  i: integer;
+  Dir: string;
+begin
+  DirectoryName:=AppendPathDelim(DirectoryName);
+  i:=1;
+  while i<=length(DirectoryName) do begin
+    if DirectoryName[i] in AllowDirectorySeparators then begin
+      // optimize paths like \foo\\bar\\foobar
+      while (i<length(DirectoryName)) and (DirectoryName[i+1] in AllowDirectorySeparators) do
+        Delete(DirectoryName,i+1,1);
+      Dir:=copy(DirectoryName,1,i-1);
+      if (Dir<>'') and not DirectoryExists(Dir) then begin
+        Result:=CreateDir(Dir);
+        if not Result then exit;
+      end;
+    end;
+    inc(i);
+  end;
+  Result:=true;
+end;
+
+function DeleteDirectory(const DirectoryName: string; OnlyChildren: boolean): boolean;
+const
+  //Don't follow symlinks on *nix, just delete them
+  DeleteMask = faAnyFile {$ifdef unix} or faSymLink{%H-} {$endif unix};
+var
+  FileInfo: TSearchRec;
+  CurSrcDir: String;
+  CurFilename: String;
+begin
+  Result:=false;
+  CurSrcDir:=AppendPathDelim(ExpandFileName(DirectoryName));
+  if FindFirst(CurSrcDir+AllFilesMask,DeleteMask,FileInfo)=0 then begin
+    try
+      repeat
+        // check if special file
+        if (FileInfo.Name='.') or (FileInfo.Name='..') or (FileInfo.Name='') then
+          continue;
+        CurFilename:=CurSrcDir+FileInfo.Name;
+        if ((FileInfo.Attr and faDirectory)>0)
+           {$ifdef unix} and ((FileInfo.Attr and faSymLink{%H-})=0) {$endif unix} then begin
+          if not DeleteDirectory(CurFilename,false) then exit;
+        end else begin
+          if not DeleteFile(CurFilename) then exit;
+        end;
+      until FindNext(FileInfo)<>0;
+    finally
+      FindClose(FileInfo);
+    end;
+  end;
+  if (not OnlyChildren) and (not RemoveDir(CurSrcDir)) then exit;
+  Result:=true;
+end;
+
+function CopyFile(const SrcFilename, DestFilename: string; Flags: TCopyFileFlags
+  ): boolean;
+var
+  SrcHandle: THandle;
+  DestHandle: THandle;
+  Buffer: array[1..4096] of byte;
+  ReadCount, WriteCount, TryCount: LongInt;
+begin
+  Result := False;
+  // check overwrite
+  if (not (cffOverwriteFile in Flags)) and FileExists(DestFileName) then begin
+    if cffExceptionOnError in Flags then
+      raise EWriteError.Create('Destination file already exists: '+DestFilename);
+    exit;
+  end;
+  // check directory
+  if (cffCreateDestDirectory in Flags)
+  and (not DirectoryExists(ExtractFilePath(DestFileName)))
+  and (not ForceDirectories(ExtractFilePath(DestFileName))) then begin
+    if cffExceptionOnError in Flags then
+      raise EWriteError.Create('Unable to create directory: '+ExtractFilePath(DestFileName));
+    exit;
+  end;
+  TryCount := 0;
+  While TryCount <> 3 Do Begin
+    SrcHandle := FileOpen(SrcFilename, fmOpenRead or fmShareDenyWrite);
+    if SrcHandle = feInvalidHandle then Begin
+      Inc(TryCount);
+      Sleep(10);
+    End
+    Else Begin
+      TryCount := 0;
+      Break;
+    End;
+  End;
+  If TryCount > 0 Then
+  begin
+    if cffExceptionOnError in Flags then
+      raise EFOpenError.CreateFmt({SFOpenError}'Unable to open file "%s"', [SrcFilename])
+    else
+      exit;
+  end;
+  try
+    DestHandle := FileCreate(DestFileName);
+    if DestHandle = feInvalidHandle then
+    begin
+      if cffExceptionOnError in Flags then
+        raise EFCreateError.CreateFmt({SFCreateError}'Unable to create file "%s"',[DestFileName])
+      else
+        Exit;
+    end;
+    try
+      repeat
+        ReadCount:=FileRead(SrcHandle,Buffer[1],High(Buffer));
+        if ReadCount<=0 then break;
+        WriteCount:=FileWrite(DestHandle,Buffer[1],ReadCount);
+        if WriteCount<ReadCount then
+        begin
+          if cffExceptionOnError in Flags then
+            raise EWriteError.CreateFmt({SFCreateError}'Unable to write to file "%s"',[DestFileName])
+          else
+            Exit;
+        end;
+      until false;
+    finally
+      FileClose(DestHandle);
+    end;
+    if (cffPreserveTime in Flags) then
+      FileSetDate(DestFilename, FileGetDate(SrcHandle));
+    Result := True;
+  finally
+    FileClose(SrcHandle);
+  end;
+end;
+
+function CopyDirTree(SrcDir, DestDir: string; Flags: TCopyFileFlags): boolean;
+var
+  FileInfo: TRawByteSearchRec;
+  SrcFilename, DestFilename: String;
+begin
+  Result:=false;
+  if not DirectoryExists(SrcDir) then begin
+    if cffExceptionOnError in Flags then
+      raise EFOpenError.Create('Source directory not found: '+SrcDir);
+    exit;
+  end;
+  if not DirectoryExists(DestDir) then begin
+    if not (cffCreateDestDirectory in Flags) then begin
+      if cffExceptionOnError in Flags then
+        raise EFOpenError.Create('Destination directory not found: '+DestDir);
+      exit;
+    end;
+    if not CreateDir(DestDir) then begin
+      if cffExceptionOnError in Flags then
+        raise EFOpenError.Create('Unable to create directory: '+DestDir);
+      exit;
+    end;
+  end;
+  SrcDir:=AppendPathDelim(SrcDir);
+  DestDir:=AppendPathDelim(DestDir);
+  if FindFirst(SrcDir+AllFilesMask,faAnyFile,FileInfo)=0 then begin
+    try
+      repeat
+        // check if special file
+        if (FileInfo.Name='.') or (FileInfo.Name='..') or (FileInfo.Name='') then
+          continue;
+        {$ifdef unix}
+        if FileInfo.Attr and faSymLink{%H-}>0 then continue;
+        {$endif unix}
+        SrcFilename:=SrcDir+FileInfo.Name;
+        DestFilename:=DestDir+FileInfo.Name;
+        if FileInfo.Attr and faDirectory>0 then begin
+          CopyDirTree(SrcFilename,DestFilename,Flags+[cffCreateDestDirectory]);
+        end else begin
+          if not CopyFile(SrcFilename, DestFilename, Flags) then
+            exit;
+        end;
+      until FindNext(FileInfo)<>0;
+    finally
+      FindClose(FileInfo);
+    end;
+  end;
+  Result:=true;
+end;
+
+initialization
+  SetMultiByteConversionCodePage(CP_UTF8);
+  // SetMultiByteFileSystemCodePage(CP_UTF8); not needed, this is the default under Windows
+  SetMultiByteRTLFileSystemCodePage(CP_UTF8);
+
+end.
+