diff --git a/src/libcalamares/PythonJob.cpp b/src/libcalamares/PythonJob.cpp
index 6944f38e5..98f284ecc 100644
--- a/src/libcalamares/PythonJob.cpp
+++ b/src/libcalamares/PythonJob.cpp
@@ -261,12 +261,12 @@ PythonJob::exec()
                 {
                     m_description.truncate( i_newline );
                 }
-                cDebug() << "Job description from __doc__" << prettyName() << '=' << m_description;
+                cDebug() << Logger::SubEntry << "Job description from __doc__" << prettyName() << '=' << m_description;
             }
         }
         else
         {
-            cDebug() << "Job description from pretty_name" << prettyName() << '=' << m_description;
+            cDebug() << Logger::SubEntry << "Job description from pretty_name" << prettyName() << '=' << m_description;
         }
         emit progress( 0 );
 
diff --git a/src/libcalamares/utils/CalamaresUtilsSystem.cpp b/src/libcalamares/utils/CalamaresUtilsSystem.cpp
index 841d52969..29f743743 100644
--- a/src/libcalamares/utils/CalamaresUtilsSystem.cpp
+++ b/src/libcalamares/utils/CalamaresUtilsSystem.cpp
@@ -188,7 +188,7 @@ System::runCommand( System::RunLocation location,
                                        : -1 ) )
     {
         cWarning() << "Process" << args.first() << "timed out after" << timeoutSec.count() << "s. Output so far:\n"
-                   << Logger::NoQuote {} << process.readAllStandardOutput();
+                   << Logger::NoQuote << process.readAllStandardOutput();
         return ProcessResult::Code::TimedOut;
     }
 
@@ -196,7 +196,7 @@ System::runCommand( System::RunLocation location,
 
     if ( process.exitStatus() == QProcess::CrashExit )
     {
-        cWarning() << "Process" << args.first() << "crashed. Output so far:\n" << Logger::NoQuote {} << output;
+        cWarning() << "Process" << args.first() << "crashed. Output so far:\n" << Logger::NoQuote << output;
         return ProcessResult::Code::Crashed;
     }
 
@@ -206,7 +206,7 @@ System::runCommand( System::RunLocation location,
     {
         if ( showDebug && !output.isEmpty() )
         {
-            cDebug() << Logger::SubEntry << "Finished. Exit code:" << r << "output:\n" << Logger::NoQuote {} << output;
+            cDebug() << Logger::SubEntry << "Finished. Exit code:" << r << "output:\n" << Logger::NoQuote << output;
         }
         else
         {
@@ -218,7 +218,7 @@ System::runCommand( System::RunLocation location,
         if ( !output.isEmpty() )
         {
             cDebug() << Logger::SubEntry << "Target cmd:" << RedactedList( args ) << "Exit code:" << r << "output:\n"
-                     << Logger::NoQuote {} << output;
+                     << Logger::NoQuote << output;
         }
         else
         {
diff --git a/src/libcalamares/utils/Logger.cpp b/src/libcalamares/utils/Logger.cpp
index 0a7dcefd0..262ff59e1 100644
--- a/src/libcalamares/utils/Logger.cpp
+++ b/src/libcalamares/utils/Logger.cpp
@@ -207,6 +207,8 @@ constexpr FuncSuppressor::FuncSuppressor( const char s[] )
 
 const constexpr FuncSuppressor Continuation( s_Continuation );
 const constexpr FuncSuppressor SubEntry( s_SubEntry );
+const constexpr NoQuote_t NoQuote {};
+const constexpr Quote_t Quote {};
 
 QString
 toString( const QVariant& v )
diff --git a/src/libcalamares/utils/Logger.h b/src/libcalamares/utils/Logger.h
index 58603c82d..a53ab7e19 100644
--- a/src/libcalamares/utils/Logger.h
+++ b/src/libcalamares/utils/Logger.h
@@ -25,15 +25,17 @@ struct FuncSuppressor
     const char* m_s;
 };
 
-struct NoQuote
+struct NoQuote_t
 {
 };
-struct Quote
+struct Quote_t
 {
 };
 
 DLLEXPORT extern const FuncSuppressor Continuation;
 DLLEXPORT extern const FuncSuppressor SubEntry;
+DLLEXPORT extern const NoQuote_t NoQuote;
+DLLEXPORT extern const Quote_t Quote;
 
 enum
 {
@@ -74,13 +76,13 @@ operator<<( QDebug& s, const FuncSuppressor& f )
 }
 
 inline QDebug&
-operator<<( QDebug& s, const NoQuote& )
+operator<<( QDebug& s, const NoQuote_t& )
 {
     return s.noquote().nospace();
 }
 
 inline QDebug&
-operator<<( QDebug& s, const Quote& )
+operator<<( QDebug& s, const Quote_t& )
 {
     return s.quote().space();
 }
@@ -254,7 +256,7 @@ operator<<( QDebug& s, const DebugMap& t )
 inline QDebug&
 operator<<( QDebug& s, const Pointer& p )
 {
-    s << NoQuote {} << '@' << p.ptr << Quote {};
+    s << NoQuote << '@' << p.ptr << Quote;
     return s;
 }
 }  // namespace Logger
diff --git a/src/libcalamares/utils/String.cpp b/src/libcalamares/utils/String.cpp
index 34a7038e3..c2a9f7bf7 100644
--- a/src/libcalamares/utils/String.cpp
+++ b/src/libcalamares/utils/String.cpp
@@ -15,6 +15,7 @@
  */
 
 #include "String.h"
+#include "Logger.h"
 
 #include <QStringList>
 
@@ -121,4 +122,60 @@ obscure( const QString& string )
     return result;
 }
 
+
+QString
+truncateMultiLine( const QString& string, CalamaresUtils::LinesStartEnd lines, CalamaresUtils::CharCount chars )
+{
+    const int maxLines = lines.atStart + lines.atEnd;
+    if ( maxLines < 1 )
+    {
+        QString shorter( string );
+        shorter.truncate( chars.total );
+        return shorter;
+    }
+
+    if ( ( string.length() <= chars.total ) && ( string.count( '\n' ) <= maxLines ) )
+    {
+        return string;
+    }
+
+    QString shorter = string;
+    QString front, back;
+    if ( shorter.count( '\n' ) >= maxLines )
+    {
+        int from = -1;
+        for ( int i = 0; i < lines.atStart; ++i )
+        {
+            from = shorter.indexOf( '\n', from + 1 );
+            if ( from < 0 )
+            {
+                // That's strange, we counted at least maxLines newlines before
+                break;
+            }
+        }
+        if ( from > 0 )
+        {
+            front = shorter.left( from + 1 );
+        }
+
+        int lastNewLine = -1;
+        int lastCount = shorter.endsWith( '\n' ) ? -1 : 0;
+        for ( auto i = shorter.rbegin(); i != shorter.rend() && lastCount < lines.atEnd; ++i )
+        {
+            if ( *i == '\n' )
+            {
+                ++lastCount;
+                lastNewLine = int( i - shorter.rbegin() );
+            }
+        }
+        if ( ( lastNewLine >= 0 ) && ( lastCount >= lines.atEnd ) )
+        {
+            back = shorter.right( lastNewLine );
+        }
+    }
+
+    return front + back;
+}
+
+
 }  // namespace CalamaresUtils
diff --git a/src/libcalamares/utils/String.h b/src/libcalamares/utils/String.h
index 48bb17aac..43e0474fa 100644
--- a/src/libcalamares/utils/String.h
+++ b/src/libcalamares/utils/String.h
@@ -61,6 +61,43 @@ DLLEXPORT QString removeDiacritics( const QString& string );
  * @return the obfuscated string.
  */
 DLLEXPORT QString obscure( const QString& string );
+
+/** @brief Parameter for counting lines at beginning and end of string
+ *
+ * This is used by truncateMultiLine() to indicate how many lines from
+ * the beginning and how many from the end should be kept.
+ */
+struct LinesStartEnd
+{
+    int atStart = 0;
+    int atEnd = 0;
+};
+
+/** @brief Parameter for counting characters in truncateMultiLine()
+ */
+struct CharCount
+{
+    int total = 0;
+};
+
+/** @brief Truncate a string to some reasonable length for display
+ *
+ * Keep the first few, or last few (or both) lines of a possibly lengthy
+ * message @p string and reduce it to a displayable size (e.g. for
+ * pop-up windows that display the message). If the message is longer
+ * than @p chars, then characters are removed from the front (if
+ * @p lines.atStart is zero) or end (if @p lines.atEnd is zero) or in the middle
+ * (if both are nonzero).
+ *
+ * @param string the input string.
+ * @param lines number of lines to preserve.
+ * @param chars maximum number of characters in the returned string.
+ * @return a string built from parts of the input string.
+ */
+DLLEXPORT QString truncateMultiLine( const QString& string,
+                                     LinesStartEnd lines = LinesStartEnd { 3, 5 },
+                                     CharCount chars = CharCount { 812 } );
+
 }  // namespace CalamaresUtils
 
 #endif
diff --git a/src/libcalamares/utils/Tests.cpp b/src/libcalamares/utils/Tests.cpp
index 6d4f5b265..3493f9579 100644
--- a/src/libcalamares/utils/Tests.cpp
+++ b/src/libcalamares/utils/Tests.cpp
@@ -13,6 +13,7 @@
 #include "Entropy.h"
 #include "Logger.h"
 #include "RAII.h"
+#include "String.h"
 #include "Traits.h"
 #include "UMask.h"
 #include "Variant.h"
@@ -63,6 +64,8 @@ private Q_SLOTS:
     void testVariantStringListYAMLDashed();
     void testVariantStringListYAMLBracketed();
 
+    /** @brief Test smart string truncation. */
+    void testStringTruncation();
 
 private:
     void recursiveCompareMap( const QVariantMap& a, const QVariantMap& b, int depth );
@@ -495,6 +498,87 @@ strings: [ aap, noot, mies ]
     QVERIFY( !getStringList( m, key ).contains( "lam" ) );
 }
 
+void
+LibCalamaresTests::testStringTruncation()
+{
+    Logger::setupLogLevel( Logger::LOGDEBUG );
+
+    using namespace CalamaresUtils;
+
+    const QString longString( R"(---
+--- src/libcalamares/utils/String.h
++++ src/libcalamares/utils/String.h
+@@ -62,15 +62,22 @@ DLLEXPORT QString removeDiacritics( const QString& string );
+  */
+ DLLEXPORT QString obscure( const QString& string );
+
++/** @brief Parameter for counting lines at beginning and end of string
++ *
++ * This is used by truncateMultiLine() to indicate how many lines from
++ * the beginning and how many from the end should be kept.
++ */
+ struct LinesStartEnd
+ {
+-    int atStart;
+-    int atEnd;
++    int atStart = 0;
++    int atEnd = 0;
+)" );
+
+    const int sufficientLength = 812;
+    // There's 18 lines in all
+    QCOMPARE( longString.count( '\n' ), 18 );
+    QVERIFY( longString.length() < sufficientLength );
+
+    // If we ask for more, we get everything back
+    QCOMPARE( longString, truncateMultiLine( longString, LinesStartEnd { 20, 0 }, CharCount { sufficientLength } ) );
+    QCOMPARE( longString, truncateMultiLine( longString, LinesStartEnd { 0, 20 }, CharCount { sufficientLength } ) );
+
+    // If we ask for no lines, only characters, we get that
+    {
+        auto s = truncateMultiLine( longString, LinesStartEnd { 0, 0 }, CharCount { 4 } );
+        QCOMPARE( s.length(), 4 );
+        QCOMPARE( s, QString( "---\n" ) );
+    }
+    {
+        auto s = truncateMultiLine( longString, LinesStartEnd { 0, 0 }, CharCount { sufficientLength } );
+        QCOMPARE( s, longString );
+    }
+
+    // Lines at the start
+    {
+        auto s = truncateMultiLine( longString, LinesStartEnd { 4, 0 }, CharCount { sufficientLength } );
+        QVERIFY( s.length() > 1 );
+        QVERIFY( longString.startsWith( s ) );
+        cDebug() << "Result-line" << Logger::Quote << s;
+        QCOMPARE( s.count( '\n' ), 4 );
+    }
+
+    // Lines at the end
+    {
+        auto s = truncateMultiLine( longString, LinesStartEnd { 0, 4 }, CharCount { sufficientLength } );
+        QVERIFY( s.length() > 1 );
+        QVERIFY( longString.endsWith( s ) );
+        cDebug() << "Result-line" << Logger::Quote << s;
+        QCOMPARE( s.count( '\n' ), 4 );
+    }
+
+    // Lines at both ends
+    {
+        auto s = truncateMultiLine( longString, LinesStartEnd { 2, 2 }, CharCount { sufficientLength } );
+        QVERIFY( s.length() > 1 );
+        cDebug() << "Result-line" << Logger::Quote << s;
+        QCOMPARE( s.count( '\n' ), 4 );
+
+        auto firsttwo = truncateMultiLine( s, LinesStartEnd { 2, 0 }, CharCount { sufficientLength } );
+        auto lasttwo = truncateMultiLine( s, LinesStartEnd { 0, 2 }, CharCount { sufficientLength } );
+        QCOMPARE( firsttwo + lasttwo, s );
+        QVERIFY( longString.startsWith( firsttwo ) );
+        QVERIFY( longString.endsWith( lasttwo ) );
+    }
+}
+
+
 QTEST_GUILESS_MAIN( LibCalamaresTests )
 
 #include "utils/moc-warnings.h"
diff --git a/src/libcalamaresui/Branding.cpp b/src/libcalamaresui/Branding.cpp
index 8145ad57c..a5038d7ee 100644
--- a/src/libcalamaresui/Branding.cpp
+++ b/src/libcalamaresui/Branding.cpp
@@ -35,7 +35,7 @@
 [[noreturn]] static void
 bail( const QString& descriptorPath, const QString& message )
 {
-    cError() << "FATAL in" << descriptorPath << Logger::Continuation << Logger::NoQuote {} << message;
+    cError() << "FATAL in" << descriptorPath << Logger::Continuation << Logger::NoQuote << message;
     ::exit( EXIT_FAILURE );
 }
 
diff --git a/src/libcalamaresui/ViewManager.cpp b/src/libcalamaresui/ViewManager.cpp
index f43152209..aaa55059e 100644
--- a/src/libcalamaresui/ViewManager.cpp
+++ b/src/libcalamaresui/ViewManager.cpp
@@ -19,6 +19,7 @@
 #include "utils/Logger.h"
 #include "utils/Paste.h"
 #include "utils/Retranslator.h"
+#include "utils/String.h"
 #include "viewpages/BlankViewStep.h"
 #include "viewpages/ExecutionViewStep.h"
 #include "viewpages/ViewStep.h"
@@ -136,15 +137,14 @@ ViewManager::insertViewStep( int before, ViewStep* step )
     emit endInsertRows();
 }
 
-
 void
 ViewManager::onInstallationFailed( const QString& message, const QString& details )
 {
     bool shouldOfferWebPaste = false;  // TODO: config var
 
-    cError() << "Installation failed:";
-    cDebug() << "- message:" << message;
-    cDebug() << "- details:" << details;
+    cError() << "Installation failed:" << message;
+    cDebug() << Logger::SubEntry << "- message:" << message;
+    cDebug() << Logger::SubEntry << "- details:" << Logger::NoQuote << details;
 
     QString heading
         = Calamares::Settings::instance()->isSetupMode() ? tr( "Setup Failed" ) : tr( "Installation Failed" );
@@ -152,7 +152,7 @@ ViewManager::onInstallationFailed( const QString& message, const QString& detail
     QString text = "<p>" + message + "</p>";
     if ( !details.isEmpty() )
     {
-        text += "<p>" + details + "</p>";
+        text += "<p>" + CalamaresUtils::truncateMultiLine( details, CalamaresUtils::LinesStartEnd{8, 0}) + "</p>";
     }
     if ( shouldOfferWebPaste )
     {