ci: simplify version number

Previously, we used `git describe --tags` to produce a version number
for non-released builds derived from the most recent tag + some info
such as the number of commits since that tag and then `g{HASH}`.

That always confuses people because the date portion at the front
looks old (it is typically the previous release) and the hash at
the end has that `g` in it.

This commit simplifies both the tag name used when making a release
and the computed version number take the date/time from the current
commit, and then append the hash.  That way the version number always
corresponds to a commit.

This scheme doesn't help detect situations where the commit is
dirty, but I don't think the old one would have helped with that
either.

ci/appimage.sh

@@ -13,8 +13,7 @@ install -Dm644 assets/wezterm.appdata.xml AppDir/usr/share/metainfo/org.wezfurlo
 
 [ -x /tmp/linuxdeploy ] || ( curl -L 'https://github.com/linuxdeploy/linuxdeploy/releases/download/continuous/linuxdeploy-x86_64.AppImage' -o /tmp/linuxdeploy && chmod +x /tmp/linuxdeploy )
 
-TAG_NAME=${TAG_NAME:-$(git describe --tags --match '20*')}
-TAG_NAME=${TAG_NAME:-$(date +'%Y%m%d-%H%M%S')-$(git log --format=%h -1)}
+TAG_NAME=${TAG_NAME:-$(git show -s "--format=%cd-%h" "--date=format:%Y%m%d-%H%M%S")}
 distro=$(lsb_release -is)
 distver=$(lsb_release -rs)
 

ci/deploy.sh

@@ -4,8 +4,7 @@ set -e
 
 TARGET_DIR=${1:-target}
 
-TAG_NAME=${TAG_NAME:-$(git describe --tags --match '20*')}
-TAG_NAME=${TAG_NAME:-$(date +'%Y%m%d-%H%M%S')-$(git log --format=%h -1)}
+TAG_NAME=${TAG_NAME:-$(git show -s "--format=%cd-%h" "--date=format:%Y%m%d-%H%M%S")}
 
 HERE=$(pwd)
 

ci/source-archive.sh

@@ -3,8 +3,7 @@
 
 set -x
 
-TAG_NAME=${TAG_NAME:-$(git describe --tags --match '20*')}
-TAG_NAME=${TAG_NAME:-$(date +'%Y%m%d-%H%M%S')-$(git log --format=%h -1)}
+TAG_NAME=${TAG_NAME:-$(git show -s "--format=%cd-%h" "--date=format:%Y%m%d-%H%M%S")}
 
 if [[ "$BUILD_REASON" == "Schedule" ]] ; then
   TAR_NAME=wezterm-nightly-src.tar

ci/tag.sh

@@ -1,4 +1,4 @@
 #!/bin/bash
-TAGNAME=$(date +'%Y%m%d-%H%M%S')-$(git log --format=%h -1)
+TAGNAME=$(git show -s "--format=%cd-%h" "--date=format:%Y%m%d-%H%M%S")
 git tag $TAGNAME
 

config/build.rs

@@ -61,7 +61,12 @@ fn main() {
             let head = head.canonicalize().unwrap();
             println!("cargo:rerun-if-changed={}", head.display());
             if let Ok(output) = std::process::Command::new("git")
-                .args(&["describe", "--tags", "--match", "20*"])
+                .args(&[
+                    "show",
+                    "-s",
+                    "--format=%cd-%h",
+                    "--date=format:%Y%m%d-%H%M%S",
+                ])
                 .output()
             {
                 let info = String::from_utf8_lossy(&output.stdout);

wezterm-gui/build.rs

@@ -68,12 +68,17 @@ fn main() {
         if let Ok(tag) = std::fs::read("../.tag") {
             if let Ok(s) = String::from_utf8(tag) {
                 ci_tag = s.trim().to_string();
-                println!("cargo:rerun-if-changed=.tag");
+                println!("cargo:rerun-if-changed=../.tag");
             }
         }
         let version = if ci_tag.is_empty() {
             let mut cmd = std::process::Command::new("git");
-            cmd.args(&["describe", "--tags"]);
+            cmd.args(&[
+                "show",
+                "-s",
+                "--format=%cd-%h",
+                "--date=format:%Y%m%d-%H%M%S",
+            ]);
             if let Ok(output) = cmd.output() {
                 if output.status.success() {
                     String::from_utf8_lossy(&output.stdout).trim().to_owned()