[wix-users] Pyro NullReference Exception

[Patrick Fay]

Wix Version: 3.10.2.2516
OS: Windows 7 x64

Hi,

I am building a patch using melt & pyro as per Bob Arnson post
<https://www.joyofsetup.com/2013/07/16/easy-pure-wix-patching-with-melt/>.
My steps include,

melt old\v1.msi -out temp\older\v1.wixpdb -pdb old\v1.wixpdb -x
temp\older\Source
melt new\v2.msi -out temp\newer\v2.wixpdb -pdb new\v2.wixpdb -x
temp\newer\Source
torch -xi temp\older\v1.wixpdb temp\newer\v2.wixpdb -out temp\diff.wixmst
candle patch.wxs
light patch.wixobj -out temp\patch.wixmsp
pyro temp\patch.wixmsp -t RTM temp\diff.wixmst -out patch.msp

However I keep getting a NullReferenceException from pyro,

pyro.exe : error PYRO0001 : Object reference not set to an instance of an
object.

Exception Type: System.NullReferenceException

Stack Trace:

   at Microsoft.Tools.WindowsInstallerXml.Patch.BuildPairedTransform(String
patchId, String clientPatchId, Output mainTransform, MediaR

   at Microsoft.Tools.WindowsInstallerXml.Patch.AttachTransforms(ArrayList
transforms)

   at Microsoft.Tools.WindowsInstallerXml.Tools.Pyro.Run(String[] args) in
C:\build\work\eca3d12b\wix3\src\tools\pyro\pyro.cs:line 212

Unhandled Exception: System.NullReferenceException: Object reference not
set to an instance of an object.

   at Microsoft.Tools.WindowsInstallerXml.Patch.BuildPairedTransform(String
patchId, String clientPatchId, Output mainTransform, MediaR

   at Microsoft.Tools.WindowsInstallerXml.Patch.AttachTransforms(ArrayList
transforms)

   at Microsoft.Tools.WindowsInstallerXml.Tools.Pyro.Run(String[] args) in
C:\build\work\eca3d12b\wix3\src\tools\pyro\pyro.cs:line 261

   at Microsoft.Tools.WindowsInstallerXml.Tools.Pyro.Main(String[] args) in
C:\build\work\eca3d12b\wix3\src\tools\pyro\pyro.cs:line 103

Is this a known bug and if so can a fix be recommended?

Thanks