Using npx gaves me errors that I don't get when I "yarn global add webpagetest"

[trollepierre]

I don't have any clues about what could be the error

[trollepierre]

Sorry, I guess the issue is due to:
webpagetest test https://my.url --first --poll --specs tools/webpagetest-threshold.json
that should be, when I run npx
webpagetest test https://my.url --first --poll --specs ./tools/webpagetest-threshold.json