fix: re-add build date to "About" page (#3464)

Co-authored-by: Felanbird <41973452+Felanbird@users.noreply.github.com>

src/CMakeLists.txt

@@ -593,6 +593,12 @@ set_target_properties(${LIBRARY_PROJECT}
     AUTOUIC ON
     )
 
+# Used to provide a date of build in the About page (for nightly builds). Getting the actual time of
+# compilation in CMake is a more involved, as documented in https://stackoverflow.com/q/24292898.
+# For CI runs, however, the date of build file generation should be consistent with the date of
+# compilation so this approximation is "good enough" for our purpose.
+string(TIMESTAMP cmake_gen_date "%Y-%m-%d")
+
 target_compile_definitions(${LIBRARY_PROJECT} PUBLIC
     CHATTERINO
     UNICODE
@@ -604,6 +610,8 @@ target_compile_definitions(${LIBRARY_PROJECT} PUBLIC
     CHATTERINO_GIT_HASH=\"${GIT_HASH}\"
     CHATTERINO_GIT_RELEASE=\"${GIT_RELEASE}\"
     CHATTERINO_GIT_COMMIT=\"${GIT_COMMIT}\"
+
+    CHATTERINO_CMAKE_GEN_DATE=\"${cmake_gen_date}\"
     )
 if (USE_SYSTEM_QTKEYCHAIN)
     target_compile_definitions(${LIBRARY_PROJECT} PUBLIC

src/common/Version.cpp

@@ -11,19 +11,15 @@ namespace chatterino {
 
 Version::Version()
 {
-    // Version
     this->version_ = CHATTERINO_VERSION;
 
-    // Commit hash
     this->commitHash_ =
         QString(FROM_EXTERNAL_DEFINE(CHATTERINO_GIT_HASH)).remove('"');
 
-    // Date of build, this is depended on the format not changing
-#ifdef CHATTERINO_NIGHTLY_VERSION_STRING
+    // Date of build file generation (≈ date of build)
+#ifdef CHATTERINO_CMAKE_GEN_DATE
     this->dateOfBuild_ =
-        QString(FROM_EXTERNAL_DEFINE(CHATTERINO_NIGHTLY_VERSION_STRING))
-            .remove('"')
-            .split(' ')[0];
+        QString(FROM_EXTERNAL_DEFINE(CHATTERINO_CMAKE_GEN_DATE)).remove('"');
 #endif
 
     // "Full" version string, as displayed in window title

src/widgets/settingspages/AboutPage.cpp

@@ -93,7 +93,7 @@ AboutPage::AboutPage()
                                     version.commitHash() + "\">" +
                                     version.commitHash() + "</a>")
                                .arg(Modes::instance().isNightly
-                                        ? ", " + version.dateOfBuild()
+                                        ? ", built on " + version.dateOfBuild()
                                         : "");
 
             auto versionLabel = versionInfo.emplace<QLabel>(text);