libutil: remove ErrorInfo::programName

it's effectively unused. one use is a write and a read immediately after
the write, the other use checks whether it's not equal to itself (..wat)

Change-Id: I5f6ce26e75a6bfa500c2e9ac3fc70e8dafc9bd74

lix/libmain/shared.cc

@@ -317,11 +317,10 @@ int handleExceptions(const std::string & programName, std::function<void()> fun)
 {
     ReceiveInterrupts receiveInterrupts; // FIXME: need better place for this
 
-    ErrorInfo::programName = baseNameOf(programName);
     /* Lix command line is not yet stabilized.
      * Explain that it is experimental and reserved for custom subcommands for now.
      * */
-    bool onlyForSubcommands = ErrorInfo::programName == "lix";
+    bool onlyForSubcommands = baseNameOf(programName) == "lix";
 
     std::string error = ANSI_RED "error:" ANSI_NORMAL " ";
     try {

lix/libutil/error.cc

@@ -33,8 +33,6 @@ const std::string & BaseError::calcWhat() const
     }
 }
 
-std::optional<std::string> ErrorInfo::programName = std::nullopt;
-
 std::ostream & operator <<(std::ostream & os, const HintFmt & hf)
 {
     return os << hf.str();
@@ -264,11 +262,7 @@ std::ostream & showErrorInfo(std::ostream & out, const ErrorInfo & einfo, bool s
             assert(false);
     }
 
-    // FIXME: show the program name as part of the trace?
-    if (einfo.programName && einfo.programName != ErrorInfo::programName)
-        prefix += fmt(" [%s]:" ANSI_NORMAL " ", einfo.programName.value_or(""));
-    else
-        prefix += ":" ANSI_NORMAL " ";
+    prefix += ":" ANSI_NORMAL " ";
 
     std::ostringstream oss;
 

lix/libutil/error.hh

@@ -89,8 +89,6 @@ struct ErrorInfo {
     unsigned int status = 1;
 
     Suggestions suggestions = {};
-
-    static std::optional<std::string> programName;
 };
 
 std::ostream & showErrorInfo(std::ostream & out, const ErrorInfo & einfo, bool showTrace);