Rename ε to "(no version)"

doc/manual/source/glossary.md

@@ -347,10 +347,6 @@
 
   The empty set symbol. In the context of profile history, this denotes a package is not present in a particular version of the profile.
 
-- [`ε`]{#gloss-epsilon}
-
-  The epsilon symbol. In the context of a package, this means the version is empty. More precisely, the derivation does not have a version attribute.
-
 - [package]{#package}
 
   A software package; files that belong together for a particular purpose, and metadata.

src/nix/diff-closures.cc

@@ -52,7 +52,7 @@ std::string showVersions(const StringSet & versions)
     if (versions.empty()) return "∅";
     StringSet versions2;
     for (auto & version : versions)
-        versions2.insert(version.empty() ? "ε" : version);
+        versions2.insert(version.empty() ? "(no version)" : version);
     return concatStringsSep(", ", versions2);
 }
 

src/nix/diff-closures.md

@@ -36,7 +36,7 @@ No size change is shown if it's below the threshold. If the package
 does not exist in either the *before* or *after* closures, it is
 represented using `∅` (empty set) on the appropriate side of the
 arrow. If a package has an empty version string, the version is
-rendered as `ε` (epsilon).
+rendered as `(no version)`.
 
 There may be multiple versions of a package in each closure. In that
 case, only the changed versions are shown. Thus,

tests/functional/nix-profile.sh

@@ -59,7 +59,7 @@ nix profile list | grep -A4 'Name:.*flake1' | grep 'Locked flake URL:.*narHash'
 (! [ -e $TEST_HOME/.nix-profile/include ])
 nix profile history
 nix profile history | grep "packages.$system.default: ∅ -> 1.0"
-nix profile diff-closures | grep 'env-manifest.nix: ε → ∅'
+nix profile diff-closures | grep 'env-manifest.nix: (no version) → ∅'
 
 # Test XDG Base Directories support
 export NIX_CONFIG="use-xdg-base-directories = true"