Cannot create property 'default' on boolean 'true'"

Version

2.6.10

Reproduction link

https://codesandbox.io/s/v8r388y7y

Steps to reproduce

When i use scope slot inside scope slot i get this error. In condsandbox i could not reproduce it, but the same code i have is there It happened when i upgraded from vue 2.6.7 -> 2.6.10

What is expected?

Not to fail

What is actually happening?

The code i have in sandbox is compiled like this

var render = function() {
  var _vm = this
  var _h = _vm.$createElement
  var _c = _vm._self._c || _h
  return _c(
    "div",
    { staticClass: "google-map" },
    [
      _c("map-loader", {
        ref: "mapLoader",
        attrs: { apiKey: _vm.apiKey, mapConfig: _vm.mapConfig },
        scopedSlots: _vm._u(
          [
            {
              key: "default",
              fn: function(ref) {
                var google = ref.google
                var map = ref.map
                return [
                  _vm._t("slot-big-slot", null, { google: google, map: map }),
                  _c(
                    "div",
                    { staticClass: "slot-container" },
                    [
                      _vm.markers.length < 2
                        ? _vm._l(_vm.markers, function(marker) {
                            return _c("google-map-marker", {
                              key: marker.lat   marker.lng,
                              attrs: {
                                marker: marker,
                                google: google,
                                map: map
                              }
                            })
                          })
                        : _vm._e(),
                      _vm.markers.length === 2
                        ? _c("route", {
                            key:
                              _vm.markers[0].lat  
                              _vm.markers[1].lat  
                              _vm.markers[0].lng  
                              _vm.markers[1].lng,
                            attrs: {
                              google: google,
                              markers: _vm.markers,
                              map: map
                            }
                          })
                        : _vm._e()
                    ],
                    2
                  )
                ]
              }
            }
          ],
          null,
          true
        )
      })
    ],
    1
  )
}
var staticRenderFns = []
render._withStripped = true

export { render, staticRenderFns }

[yyx990803]

You probably have either own code or 3rd party code that was compiled using an outdated version of vue-template-compiler.

[klimentLambevski]

@yyx990803 @sirlancelot @posva I had vue-template-compiler version 2.6.6 in my dev dependencies 🤦‍♂️, Sorry for wasting your time, I will leave you alone now