Codefirst migrations: foreign keys deleted and re-added every time

[joshuapetryk]

asp.net 5/core 1 project, dnx 1.0.0-rc1-16609

"dependencies": {
    "EntityFramework.Commands": "7.0.0-rc1-final",
    "EntityFramework.MicrosoftSqlServer": "7.0.0-rc1-final",
    "Microsoft.AspNet.Identity.EntityFramework": "3.0.0-rc1-final"
//etc..
},

Initial Migration:

            migrationBuilder.CreateTable(
                name: "AspNetRoleClaims",
                columns: table => new
                {
                    Id = table.Column<int>(nullable: false)
                        .Annotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn),
                    ClaimType = table.Column<string>(nullable: true),
                    ClaimValue = table.Column<string>(nullable: true),
                    RoleId = table.Column<string>(nullable: false)
                },
                constraints: table =>
                {
                    table.PrimaryKey("PK_IdentityRoleClaim<string>", x => x.Id);
                    table.ForeignKey(
                        name: "FK_IdentityRoleClaim<string>_IdentityRole_RoleId",
                        column: x => x.RoleId,
                        principalTable: "AspNetRoles",
                        principalColumn: "Id",
                        onDelete: ReferentialAction.Cascade);
                });

Any migration I run after the initial is producing this sort of code:

protected override void Up(MigrationBuilder migrationBuilder)
{
    migrationBuilder.DropForeignKey(name: "FK_IdentityRoleClaim<string>_IdentityRole_RoleId", table: "AspNetRoleClaims");
//etc..

    migrationBuilder.AddForeignKey(
                name: "FK_IdentityRoleClaim<string>_IdentityRole_RoleId",
                table: "AspNetRoleClaims",
                column: "RoleId",
                principalTable: "AspNetRoles",
                principalColumn: "Id",
                onDelete: ReferentialAction.Cascade);
// etc.

And the snapshot:

protected override void BuildModel(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity("Microsoft.AspNet.Identity.EntityFramework.IdentityRoleClaim<string>", b =>
                {
                    b.HasOne("Microsoft.AspNet.Identity.EntityFramework.IdentityRole")
                        .WithMany()
                        .HasForeignKey("RoleId");
                });

Why is EF deleting and re-added the same FK constraints every time I add a migration?

[joshuapetryk]

Nevermind, after tearing my hair out for a while I finally found it's a known issue.
#3751

[smitpatel]

actually dupe of #3751 & #4325, fixed in #3756 & #4349 will be available in RC2 release.