Build fails on Windows with PowerShell

[fwextensions]

I cloned the repo, installed deno 1.38.0, and ran deno task build:

❯ deno task build
Task build deno run --allow-all --unstable './tasks/build.ts'
Warning Implicitly using latest version (0.205.0) for https://deno.land/std/testing/asserts.ts
error: Uncaught (in promise) Error: %1 is not a valid Win32 application. (os error 193)
          const result = await Deno.run({ cmd }).status()
                                    ^
    at opRun (ext:runtime/40_process.js:50:14)
    at Object.run (ext:runtime/40_process.js:136:15)
    at file:///C:/Projects/Chrome%20Extensions/json-formatter/tasks/lib/compile.ts:44:37
    at Array.map (<anonymous>)
    at file:///C:/Projects/Chrome%20Extensions/json-formatter/tasks/lib/compile.ts:34:24
    at eventLoopTick (ext:core/01_core.js:183:11)
    at async https://deno.land/x/wire@v2.0.0-alpha.2/core/tmp.ts:47:5
    at async subsetTransform (https://deno.land/x/wire@v2.0.0-alpha.2/core/subset.ts:19:20)
    at async subsetTransform (https://deno.land/x/wire@v2.0.0-alpha.2/core/subset.ts:19:20)
    at async pipedTransform (https://deno.land/x/wire@v2.0.0-alpha.2/core/pipe.ts:21:25)

Looks like there's an issue with how the args are passed to the command line, but I don't know enough about deno to try to debug it.