nicer merge output

src/evalable.cpp

 #include "evalable.h"
 #include "measurements.h"
 #include <fmt/format.h>
-#include <iostream>
 #include <map>
 
 namespace loadl {
@@ -43,10 +42,7 @@ observable_result evaluator::jackknife(const std::string &name,
 	size_t bin_count = -1; // maximal value
 	for(const auto &obs_name : used_observables) {
 		if(res_.observables.count(obs_name) <= 0) {
-			std::cerr << fmt::format(
-			    "Warning: evalable '{}': used observable '{}' not found in Monte Carlo results. "
-			    "Skipping...\n",
-			    name, obs_name);
+			// skip evalable if ingredients are missing from the measurements
 			return obs_res;
 		}
 		const auto &obs = res_.observables.at(obs_name);

src/loadleveller.h

@@ -4,15 +4,23 @@
 #include "merger.h"
 #include "runner.h"
 #include "runner_single.h"
-
 namespace loadl {
 
 inline int merge_only(jobinfo job, const mc_factory &, int, char **) {
+	int ntasks = job.task_names.size();
+	int len = log(ntasks)/log(10)+1;
+	size_t max_tasklen = 0;
+
 	for(size_t task_id = 0; task_id < job.task_names.size(); task_id++) {
-		job.merge_task(task_id);
+		std::string taskdir = job.taskdir(task_id);
+		max_tasklen = std::max(max_tasklen, taskdir.size());
 
-		std::cout << fmt::format("-- {} merged\n", job.taskdir(task_id).string());
+		std::cout << fmt::format("\rMerging task {0: >{3}}/{1: >{3}}... {2: <{4}}", task_id+1, job.task_names.size(), taskdir, len, max_tasklen);
+		std::cout.flush();
+
+		job.merge_task(task_id);
 	}
+	std::cout << fmt::format("\rMerged {0} tasks.{1: >{2}}\n", job.task_names.size(), "", 2*len+5+max_tasklen);
 
 	return 0;
 }