Cannot read property 'replace' of undefined

[tajchert]

I wanted to use Positron project.yml from CartoDB/basemap-styles as my style, and preview it in Kosmtik.
After running
kosmtik serve ~/basemap-styles-master/cartocss/web-styles/positron.tm2/project.yml
And opening local host in browser on Kosmtik port:
http://127.0.0.1:6789/positron.tm2/#15/37.8011/-122.4703
I get:

/usr/local/lib/node_modules/kosmtik/src/back/Utils.js:36
        return str.replace(/\{ *([\w_]+) *\}/g, function (str, key) {
                   ^

TypeError: Cannot read property 'replace' of undefined
    at Object.template (/usr/local/lib/node_modules/kosmtik/src/back/Utils.js:36:20)
    at VectorBasedTile._render (/usr/local/lib/node_modules/kosmtik/src/back/VectorBasedTile.js:52:24)
    at VectorBasedTile.render (/usr/local/lib/node_modules/kosmtik/src/back/VectorBasedTile.js:112:10)
    at /usr/local/lib/node_modules/kosmtik/src/back/ProjectServer.js:78:21
    at /usr/local/lib/node_modules/kosmtik/node_modules/generic-pool/lib/generic-pool.js:291:11
    at loaded (/usr/local/lib/node_modules/kosmtik/node_modules/mapnik-pool/index.js:27:28)
[1]    14946 segmentation fault  kosmtik serve

Import of the style is fine (output):

[Core] No usable config file found in /Users/mtajchert/.config/kosmtik.yml
[Core] Loading plugin from ../plugins/base-exporters/index.js
[Core] Loading plugin from ../plugins/hash/index.js
[Core] Loading plugin from ../plugins/local-config/index.js
[Core] Loading plugin from ../plugins/datasource-loader/index.js
[Core] Loading project from /Users/mtajchert/Downloads/basemap-styles-master/cartocss/web-styles/positron.tm2/project.yml
[Core] PreviewServer started, you can browse http://127.0.0.1:6789
[Core] Creating metatiles cache dir tmp/positron.tm2/meta
[Core] Deleting previous metatiles tmp/positron.tm2/meta
[Core] Created vector cache dir tmp/positron.tm2/vector
[Local Config] Unable to load local config from /Users/mtajchert/Downloads/basemap-styles-master/cartocss/web-styles/positron.tm2/localconfig.js
[Error: File not found: /Users/mtajchert/Downloads/basemap-styles-master/cartocss/web-styles/positron.tm2/localconfig.js]
[Core] Generating Mapnik XML…
[Core] Using mapnik version 3.0.20
[Core] Loading map…
[Core] Map ready
[Core] Loading map…
[Core] Map ready

Installed Kosmtik with Node 9.11.1 on MacOS Big Sur via NPM.
According to #275 Error: File not found: /Users/mtajchert/Downloads/basemap-styles-master/cartocss/web-styles/positron.tm2/localconfig.js is optional and is not an error that affect proper working also export of XML works fine.

[tajchert]

This turned out to be an issue with schema URL inside Positron file (URL is not reachable).
URL http://fast.nutiteq.com/v3.json in line https://github.com/CartoDB/basemap-styles/blob/master/cartocss/web-styles/positron.tm2/project.yml#L36
Solution was to replace that one with one from Voyager style (as it works).

With that I'm closing this issue as this seems like a Positron style bug and not Kosmtik.