*Pivot() methods are not available in when() when querying a relationship

[Imangazaliev]

• Laravel Version: 8.48
• PHP Version: 8.0
• Database Driver & Version: PostgreSQL 12.8

Description:

There's User model with Role many-to-many relationship:

public function roles(): BelongsToMany
{
    return $this->belongsToMany(Role::class, 'roles_users', 'user_id', 'role_id');
}

I want to add a conditinal clause for a pivot column to a relationship query:

$roleIds = $user
    ->roles()
    ->withPivotValue()
    ->when($languageId !== null, function (Builder $query) use ($languageId) {
        $query->wherePivot('language_id', $languageId);
    })
    ->where(function (Builder $query) {
        $query->orWherePivotNull('language_id');
    })
    ->pluck('roles.id')
;

But gettig the error:

SQLSTATE[42703]: Undefined column: 7 ERROR:  column "pivot" does not exist                                                                                                
  LINE 1: ...."role_id" where "roles_users"."user_id" = $1 and "pivot" = ...                                                                                                
                                                               ^ (SQL: select "roles"."id" from "roles" inner join "roles_users" on "roles"."id" = "roles_users"."role_id"  
   where "roles_users"."user_id" = 300005 and "pivot" = language_id or "roles_users"."language_id" is null)

If comment out when I'm getting the following error because nested orWherePivotNull:

Call to undefined method Illuminate\Database\Eloquent\Builder::orWherePivotNull()