将第三方库导入角度库时出错

正在尝试使用ng packager创建库。

在我运行的项目内部:

ng g library nt select--前缀nt

在nt-select.component.ts中

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'nt-nt-select',
  template: `
    <mat-form-field>
      <mat-select [placeholder]="placeholder" [disabled]="disabled" [multiple]="multiple" [(ngModel)]="value"
                  [required]="required">

        <ngx-mat-select-search *ngIf="searchable"
                               [formControl]="optionFilterCtrl"
                               [placeholderLabel]="'Axtar'"
                               [noEntriesFoundLabel]="'Tapılmadı'"
                               [clearSearchInput]="false"
        ></ngx-mat-select-search>
        <mat-option *ngFor="let opt of filteredOptions$ | async" [value]="opt.value">
          {{opt.label}}
        </mat-option>
      </mat-select>

      <mat-error>{{getErrors('hobbies')}}</mat-error>
    </mat-form-field>

  `,
  styles: []
})
export class NtSelectComponent implements OnInit {

  constructor() { }

  ngOnInit() {
  }

}

和nt.select.module:

import { NgModule } from '@angular/core';
import { NtSelectComponent } from './nt-select.component';
import {CommonModule} from '@angular/common';
import {BrowserAnimationsModule} from '@angular/platform-browser/animations';
import {FormsModule, ReactiveFormsModule} from '@angular/forms';
import {MatSelectModule} from '@angular/material';
import {NgxMatSelectSearchModule} from 'ngx-mat-select-search';

@NgModule({
  imports: [
    CommonModule,
    BrowserAnimationsModule,
    MatSelectModule,
    NgxMatSelectSearchModule,
    ReactiveFormsModule,
    FormsModule
  ],
  declarations: [NtSelectComponent],
  exports: [NtSelectComponent]
})
export class NtSelectModule { }

问题是nt select emits error cannot find name of Mat窗体字段,Mat Select,NGX Mat Select搜索 即使我导入了所有模块。
以下教程介绍: https://blog.angularindepth.com/creating-a-library-in-angular-6-87799552e7e5
可能是什么问题?
提前谢谢