Custom metadata type not accessible after installation with sfdx

Question

I create an app using sfdx and at one point I convert it as a package using:

• sfdx force:source:convert --outputdir mdapi_packageName --packagename packageName
• and installing on a (other) org using sfdx force:mdapi:deploy --deploydir mdapi_packageName --targetusername username.

My package contains custom metatadata type with two String fields and one record. The goal is to let user (System admin) fill the content of this record after installation but those two fields are not accessible in setup.

Metadata definition:

<?xml version="1.0" encoding="UTF-8"?>
<CustomObject xmlns="http://soap.sforce.com/2006/04/metadata">
    <description>Description</description>
    <label>Label</label>
    <pluralLabel>Descriptions</pluralLabel>
    <visibility>Public</visibility>
</CustomObject>

Record:

<?xml version="1.0" encoding="UTF-8"?>
<CustomMetadata xmlns="http://soap.sforce.com/2006/04/metadata" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <label>Record</label>
    <protected>false</protected>
    <values>
        <field>fieldA__c</field>
        <value xsi:type="xsd:string"></value>
    </values>
    <values>
        <field>fieldB__c</field>
        <value xsi:type="xsd:string"></value>
    </values>
</CustomMetadata>

I can't find documentation I read yesterday but it seems that user need a permission (via permission set or profile) to be able to do it (Customize Application if I remember correctly) and it is set but still not working.

Edit: I miss the field definition from other files with sfdx:

Metadata 1:

<?xml version="1.0" encoding="UTF-8"?>
<CustomField xmlns="http://soap.sforce.com/2006/04/metadata">
    <fullName>FieldA__c</fullName>
    <externalId>false</externalId>
    <fieldManageability>SubscriberControlled</fieldManageability>
    <label>Field A</label>
    <length>255</length>
    <required>false</required>
    <type>Text</type>
    <unique>false</unique>
</CustomField>

Metadata 2:

<?xml version="1.0" encoding="UTF-8"?>
<CustomField xmlns="http://soap.sforce.com/2006/04/metadata">
    <fullName>FieldB__c</fullName>
    <externalId>false</externalId>
    <fieldManageability>SubscriberControlled</fieldManageability>
    <label>Field B</label>
    <length>255</length>
    <required>false</required>
    <type>Text</type>
    <unique>false</unique>
</CustomField>

Answer 1

Seems to me like the metadata file that describes your custom metadata type is missing something.

If you take a look at the Custom Metadata Type documentation (from the metadata api), we do have the ability to specify fields.

In fact, the example xml file given contains a custom field:

<?xml version="1.0" encoding="UTF-8"?>
<CustomObject xmlns="http://soap.sforce.com/2006/04/metadata">
   <fields>
      <fullName>AlphaSort__c</fullName>
      <defaultValue>false</defaultValue>
      <externalId>false</externalId>
      <label>Sorted Alphabetically</label>
      <type>Checkbox</type>
   </fields>
   <label>Reusable Picklist</label>
   <pluralLabel>Reusable Picklist</pluralLabel>
   <visibility>Public</visibility>
</CustomObject>

I don't see any custom fields defined in your metadata file. If your custom setting did not exist in your target org prior to your deployment through sfdx, then I'd expect that the metadata you've provided would create the custom metadata type with no fields.

The bit about needing the Customize Application permission seems to come from the "field manageability" options for fields of custom metadata types.

About the only explanation that I can think of for why your custom metadata type xml file ended up the way it did was that the "source form" for your custom metadata type did not contain the "fields" sub-folder. Alternatively, if you created the custom metadata type in a scratch org, and had the "fields" sub-folder in your .forceignore file, then sfdx force:source:pull would have ignored it and just given you the barest of metadata for the custom metadata type itself.

Answer 2

Do you possibly mean that the fields do not appear when you try to view or create new records of this Custom Metadata Type? One thing I noticed with Custom Metadata types is, the page layout assignments live on Profiles. So if you deployed this stuff in a new org, its Profiles might have no Page Layout Assignments for this CM type. In which case the create/view/edit pages will have no fields on them.