GalleryManifest FilePathKind Does Not Take Precedence over _NT_DEBUGGER_EXTENSION_PATH

[trustednstaller]

The Absolute element in File is not respected and never read e.g.,

        <BinaryComponent Name="Extension" Type="Engine">
            <Files>
                <File Architecture="amd64" Module="c:\my\absolute\path\Extension.dll" FilePathKind="Absolute" />
            </Files>
            <LoadTriggers>
                <TriggerSet>
                    <AlwaysTrigger Name="Yes" />
                </TriggerSet>
            </LoadTriggers>
        </BinaryComponent>

the above does not load through the gallery manifest even though it gets processed. However, if I make the absolute path part of the _NT_DEBUGGER_EXTENSION_PATH, then it does get loaded. There appears to be an issue in where the absolute path is not respected but the base name of the extension is nonetheless found as the engine checks the (custom) debugger extension path.

[trustednstaller]

Okay, so it is not limited to the Absolute file path kind. When I specify RepositoryRelative, _NT_DEBUGGER_EXTENSION_PATH takes precedence:

<?xml version="1.0" encoding="utf-8"?>
<ExtensionPackages Version="1.0.0.0" Compression="none">
  <ExtensionPackage>
    <Name>Xng</Name>
    <Version>1.0.0.1</Version>
    <MinDebuggerSupported>10.0.17074.1002</MinDebuggerSupported>
    <Description>Xng Windbg Extension Framework</Description>
    <Components>
        <BinaryComponent Name="Extension" Type="Engine">
            <Files>
                <File Architecture="amd64" Module="winext\Extension.dll" FilePathKind="RepositoryRelative" />
            </Files>
            <LoadTriggers>
                <TriggerSet>
                    <AlwaysTrigger Name="Yes" />
                </TriggerSet>
            </LoadTriggers>
        </BinaryComponent>
    </Components>
  </ExtensionPackage>
</ExtensionPackages>

Running the debugger (command line version):

>> c:\dbg\cdb.exe notepad

... snip snip ...

(50d78.57080): Break instruction exception - code 80000003 (first chance)
ntdll!LdrpDoDebuggerBreak+0x35:
00007ff9`abb61429 cc              int     3
0:000> .chain
Extension DLL chain:
    Extension: API 0.0.0, built Tue Apr  8 20:12:11 2025
        [path: C:\users\SharedDrive\extensions\Extension.dll]   <======
    dbghelp: image 10.0.27596.1000, API 10.0.6,
        [path: C:\dbg\dbghelp.dll]
    exts: image 10.0.27596.1000, API 1.0.0,
        [path: C:\dbg\WINXP\exts.dll]
    uext: image 10.0.27596.1000, API 1.0.0,
        [path: C:\dbg\winext\uext.dll]
0:000>

The extension is specified as relative (winext\Extension.dll) but because the base name of the extension is found inside the _NT_DEBUGGER_EXTENSION_PATH, this takes precedence.

[TedyHH]

trustednstaller (@trustednstaller) - Can you please clarify in which folder did you put the manifest file and how it was named in that folder?
Thanks!

[trustednstaller]

Found out after Tedy Hroulev (@TedyHH) s (indirect) suggestion that the issue only applies to when you add a gallery manifest XML into the OptionalExtensions directory for a supported architecture type. Creating one's own gallery (in the documented manner) or using the $env:LOCALAPPDATA\DBG\UserExtensions directory does not invoke the issue described above.

I had reasons for using OptionalExtensions but not sure if this would still be classified as the same bug or if OptionalExtensions is meant to be used by users directly. If not, please feel free to close this issue as completed.