Swift Stack View horizontal UIlabels not filling properly

Question

So I am designing what should be a simple view.

This is how I want it to be, with the title taking up only the horizontal space that it needs. However, when I set the number of lines for the Details view to 0 so that it can be multiple lines, or when I do the same for the title label, I automatically get this:

I do like using a Stack View for these labels, because it seems the most natural choice to account for dynamic text. All that I would have to do when the text gets larger is change the axis to vertical. I have already set the hugging priority of the title label to 252 and I have already set a proportionate widths constraint so that the details will have a greater or equal width to the title.

So there is no ambiguity for the widths of the labels

• the title label width should equal the width of its contents, until the contents reach the point that they would exceed the width of the details label, then word wrap.

• The details label should should have a width equal to its contents as well, until it would exceed the bounds allowed by the higher priority hugging on the left and the trailing constraint on the right, then it should word wrap.

Here is my xib as an xml source code

<?xml version="1.0" encoding="UTF-8"?>
<document type="com.apple.InterfaceBuilder3.CocoaTouch.XIB" version="3.0" toolsVersion="18122" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES">
    <device id="retina6_1" orientation="portrait" appearance="light"/>
    <dependencies>
        <deployment identifier="iOS"/>
        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="18093"/>
        <capability name="Safe area layout guides" minToolsVersion="9.0"/>
        <capability name="System colors in document resources" minToolsVersion="11.0"/>
        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
    </dependencies>
    <objects>
        <placeholder placeholderIdentifier="IBFilesOwner" id="-1" userLabel="File's Owner"/>
        <placeholder placeholderIdentifier="IBFirstResponder" id="-2" customClass="UIResponder"/>
        <view contentMode="scaleToFill" id="iN0-l3-epB">
            <rect key="frame" x="0.0" y="0.0" width="372" height="76"/>
            <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
            <subviews>
                <stackView opaque="NO" contentMode="scaleToFill" spacing="5" translatesAutoresizingMaskIntoConstraints="NO" id="pIM-2q-cOU">
                    <rect key="frame" x="0.0" y="0.0" width="372" height="76"/>
                    <subviews>
                        <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="252" verticalHuggingPriority="251" text="Title" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="G5U-AG-1Se">
                            <rect key="frame" x="0.0" y="0.0" width="33" height="76"/>
                            <fontDescription key="fontDescription" type="system" pointSize="17"/>
                            <nil key="textColor"/>
                            <nil key="highlightedColor"/>
                        </label>
                        <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="asasdf;lkj;lkjasdf" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="pjO-IR-TuP">
                            <rect key="frame" x="38" y="0.0" width="334" height="76"/>
                            <fontDescription key="fontDescription" type="system" pointSize="17"/>
                            <nil key="textColor"/>
                            <nil key="highlightedColor"/>
                        </label>
                    </subviews>
                </stackView>
            </subviews>
            <viewLayoutGuide key="safeArea" id="vUN-kp-3ea"/>
            <color key="backgroundColor" systemColor="systemBackgroundColor"/>
            <constraints>
                <constraint firstAttribute="bottom" secondItem="pIM-2q-cOU" secondAttribute="bottom" id="1y4-EF-89I"/>
                <constraint firstItem="pIM-2q-cOU" firstAttribute="leading" secondItem="iN0-l3-epB" secondAttribute="leading" id="6n3-Qg-845"/>
                <constraint firstItem="pIM-2q-cOU" firstAttribute="top" secondItem="iN0-l3-epB" secondAttribute="top" id="Ey8-Pq-GRr"/>
                <constraint firstAttribute="trailing" secondItem="pIM-2q-cOU" secondAttribute="trailing" id="O6p-XR-VEs"/>
                <constraint firstItem="vUN-kp-3ea" firstAttribute="trailing" secondItem="pIM-2q-cOU" secondAttribute="trailing" id="Z5d-jc-cwM"/>
            </constraints>
            <freeformSimulatedSizeMetrics key="simulatedDestinationMetrics"/>
            <variation key="default">
                <mask key="constraints">
                    <exclude reference="O6p-XR-VEs"/>
                </mask>
            </variation>
            <point key="canvasLocation" x="-16" y="-101"/>
        </view>
    </objects>
    <resources>
        <systemColor name="systemBackgroundColor">
            <color white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
        </systemColor>
    </resources>
</document>

Answer 1

If you set the content hugging priority of the left label to 1000 (Required), it works.

There might be something with a very high priority in the stack view that is stopping the label from hugging its content.