stack/packages/cli/tests/stack-copy.test.mjs

import test from 'node:test';
import assert from 'node:assert/strict';
import {execFileSync,spawnSync,spawn} from 'node:child_process';
import {symlinkSync,unlinkSync,mkdtempSync,mkdirSync,writeFileSync,readFileSync,cpSync,rmSync,chmodSync,existsSync,statSync} from 'node:fs';
import {tmpdir} from 'node:os';
import {join,dirname} from 'node:path';
import {fileURLToPath} from 'node:url';
import {once} from 'node:events';
import {pathToFileURL} from 'node:url';
import {fixture,notifyConfig,BUSINESSES} from './helpers.mjs';
const ROOT=fileURLToPath(new URL('../../..',import.meta.url)).replace(/\/$/,'');
const git=(cwd,...args)=>execFileSync('git',['-c','user.name=fixture','-c','user.email=fixture@invalid','-c','commit.gpgsign=false','-c','core.hooksPath=/dev/null','-C',cwd,...args],{encoding:'utf8'}).trim();
export function setup(t, realPin=false){
 const root=mkdtempSync(join(tmpdir(),'stack-copy-')),repo=join(root,'repo'),copies=join(root,'copies'),bin=join(root,'bin');
 t.after(()=>{execFileSync('chmod',['-R','u+w',root]);rmSync(root,{recursive:true,force:true})});
 mkdirSync(repo);mkdirSync(bin);
 const tracked=execFileSync('git',['-C',ROOT,'ls-files','-co','--exclude-standard','--','scripts','packages','adapters','roles','RELEASE','package.json','package-lock.json',':!packages/*/tests',':!scripts/foundation'],{encoding:'utf8'}).trim().split('\n');
 for(const f of tracked)if(existsSync(join(ROOT,f)))cpSync(join(ROOT,f),join(repo,f));
 // Lightweight npm-ci fixture; real pin/host/proof integration is tested separately.
 const pkg={name:'copy-fixture',version:'1.0.0'};
 if(!realPin){writeFileSync(join(repo,'package.json'),JSON.stringify(pkg));
 writeFileSync(join(repo,'package-lock.json'),JSON.stringify({name:pkg.name,version:pkg.version,lockfileVersion:3,packages:{'':pkg}}));}
 else {for(const f of ['package.json','package-lock.json'])cpSync(join(ROOT,f),join(repo,f));}
 git(repo,'init','-q','-b','refactor');git(repo,'config','gc.auto','0');git(repo,'add','.');git(repo,'commit','-qm','fixture');
 const id=git(repo,'rev-parse','HEAD');git(repo,'update-ref','refs/remotes/origin/refactor',id);
 const env={PATH:`${bin}:${dirname(process.execPath)}:/usr/bin:/bin`,HOME:root,XDG_DATA_HOME:join(root,'data'),XDG_CONFIG_HOME:join(root,'config')};
 const search=join(root,'unit-search');mkdirSync(search);
 const analyze=body=>{writeFileSync(join(bin,'systemd-analyze'),'#!/bin/sh\n'+body);chmodSync(join(bin,'systemd-analyze'),0o755);};
 analyze(`printf '%s\\n' '${search}'\n`);
 const run=(script,args=[])=>spawnSync(join(repo,'scripts',script),args,{env,encoding:'utf8',timeout:30000});
 const fake=body=>{writeFileSync(join(bin,'systemctl'),'#!/bin/bash\n'+body);chmodSync(join(bin,'systemctl'),0o755)};
 return {root,repo,copies,bin,id,env,run,fake,search,analyze};
}
test('shared copy: npm ci, pushed reachability, readonly/existing copy, webui delegation',t=>{
 const s=setup(t),r=s.run('stack-copy.sh',['copy',s.id,'--copies',s.copies]);assert.equal(r.status,0,r.stderr);
 const copy=join(s.copies,s.id);assert.equal(statSync(copy).mode&0o777,0o555);
 for(const f of ['scripts/mosaic','adapters/pi/adapter.sh','packages/queue/src/cli.mjs','package.json','package-lock.json','packages/tasks/requirements.json','packages/plugins/src/kinds.mjs','packages/plugins/src/loader.mjs'])assert.ok(existsSync(join(copy,f)),f);
 const npm=join(s.bin,'npm');writeFileSync(npm,'#!/bin/sh\nexit 99\n');chmodSync(npm,0o755);
 const existing=s.run('webui-service.sh',['copy',s.id,'--copies',s.copies]);assert.equal(existing.status,0);assert.equal(existing.stdout,`exists: ${copy}\n`);unlinkSync(npm);
 git(s.repo,'update-ref','refs/remotes/origin/refactor',git(s.repo,'hash-object','-w','package.json'));
 const denied=s.run('stack-copy.sh',['copy',s.id,'--copies',s.copies]);assert.notEqual(denied.status,0);assert.match(denied.stderr,/origin\/refactor/);
});
test('wrapper preserves Q81 lease and marker, rejects foreign/symlink; check uses effective roots',t=>{
 const s=setup(t);assert.equal(s.run('stack-copy.sh',['copy',s.id,'--copies',s.copies]).status,0);
 const wrapper=join(s.bin,'mosaic'),marker='# mosaic-cli wrapper (Q81, agents/sage/work/q81/mosaic-cli.sh)';
 const lease=`[ "\${1:-}" = __lease-capability ] && exec "${s.bin}/mosaic-old" "$@"`;
 writeFileSync(wrapper,`#!/usr/bin/env bash\n${marker}\n${lease}\nexec "/old/scripts/mosaic" "$@"\n`);
 assert.equal(s.run('stack-copy.sh',['wrapper',s.id,'--copies',s.copies,'--bin',s.bin]).status,0);
 const lines=readFileSync(wrapper,'utf8').trimEnd().split('\n');
 assert.equal(lines[1],marker);
 assert.equal(lines[2],`# CLI runs from pinned copy: ${join(s.copies,s.id)}`);
 assert.equal(lines[3],'# The Q81 lease probe still answers at mosaic-old.');
 assert.equal(lines.at(-1),`exec "${join(s.copies,s.id)}/scripts/mosaic" "$@"`);
 assert.match(readFileSync(wrapper,'utf8'),new RegExp(s.id));assert.ok(readFileSync(wrapper,'utf8').includes(lease));
 const old=join(s.bin,'mosaic-old');writeFileSync(old,'#!/bin/sh\nprintf \"legacy:%s\\n\" \"$1\"\n');chmodSync(old,0o755);
 assert.equal(spawnSync(wrapper,['__lease-capability'],{env:s.env,encoding:'utf8'}).stdout,'legacy:__lease-capability\n');
 const copy=join(s.copies,s.id);s.fake(`case "$*" in *mosaic-bus*) echo 'LoadState=loaded'; echo 'WorkingDirectory=${copy}'; echo 'ExecStart={ path=${copy}/scripts/mosaic ; argv[]=${copy}/scripts/mosaic bus start mosaic-stack --pm ; }';; *) echo 'LoadState=loaded'; echo 'WorkingDirectory=${copy}'; echo 'ExecStart={ path=/usr/bin/node ; argv[]=/usr/bin/node ${copy}/packages/webui/src/cli.mjs serve ; }';; esac\n`);
 assert.equal(s.run('stack-copy.sh',['check','--copies',s.copies,'--bin',s.bin]).status,0);
 s.fake(`echo 'LoadState=loaded'; echo 'WorkingDirectory=${copy}';case \"$*\" in *mosaic-bus*)echo 'ExecStart={ path=/other/scripts/mosaic ; argv[]=/other/scripts/mosaic bus start demo ; }';; *)echo 'ExecStart={ path=/usr/bin/node ; argv[]=/usr/bin/node ${copy}/packages/webui/src/cli.mjs serve ; }';;esac\n`);
 assert.equal(s.run('stack-copy.sh',['check','--copies',s.copies,'--bin',s.bin]).status,1,'effective ExecStart mismatch');
 s.fake(`echo 'LoadState=loaded'; echo 'WorkingDirectory=/other';\n`);assert.equal(s.run('stack-copy.sh',['check','--copies',s.copies,'--bin',s.bin]).status,1);
 const foreign=`#!/usr/bin/env bash\n# foreign wrapper\n${lease}\nexec \"${copy}/scripts/mosaic\" \"$@\"\n`;writeFileSync(wrapper,foreign);
 // Restore matching effective roots: only the foreign marker refuses check.
 s.fake(`echo 'LoadState=loaded';echo 'WorkingDirectory=${copy}';case "$*" in *mosaic-bus*) echo 'ExecStart={ path=${copy}/scripts/mosaic ; argv[]=${copy}/scripts/mosaic bus start demo ; }';; *)echo 'ExecStart={ path=/usr/bin/node ; argv[]=/usr/bin/node ${copy}/packages/webui/src/cli.mjs serve ; }';;esac\n`);
 assert.equal(s.run('stack-copy.sh',['check','--copies',s.copies,'--bin',s.bin]).status,1);
 assert.notEqual(s.run('stack-copy.sh',['wrapper',s.id,'--copies',s.copies,'--bin',s.bin]).status,0);assert.equal(readFileSync(wrapper,'utf8'),foreign);
 const backing=join(s.bin,'backing');writeFileSync(backing,`#!/usr/bin/env bash\n${marker}\n${lease}\nexec \"/old/scripts/mosaic\" \"$@\"\n`);unlinkSync(wrapper);symlinkSync(backing,wrapper);assert.notEqual(s.run('stack-copy.sh',['wrapper',s.id,'--copies',s.copies,'--bin',s.bin]).status,0);
});
test('bus unit copy/pm pins, install refuses all busy states and failed reads, drop-in refusal',t=>{
 const s=setup(t);assert.equal(s.run('stack-copy.sh',['copy',s.id,'--copies',s.copies]).status,0);
 const args=['--copy',s.id,'--copies',s.copies,'--pm'];
 const render=s.run('bus-service.sh',['render',...args]);assert.equal(render.status,0,render.stderr);assert.match(render.stdout,new RegExp(`WorkingDirectory=${s.copies}/${s.id}`));assert.match(render.stdout,/bus start %i --pm/);
 const units=join(s.root,'units');
 for(const state of ['active','activating','deactivating','reloading']){s.fake(`echo '[email protected] loaded ${state} running fixture';\n`);const r=s.run('bus-service.sh',['install',...args,'--dir',units,'--no-reload']);assert.notEqual(r.status,0,state);assert.ok(!existsSync(units));}
 s.fake('exit 1\n');assert.notEqual(s.run('bus-service.sh',['install',...args,'--dir',units,'--no-reload']).status,0);assert.ok(!existsSync(units));
 const dropdir=join(s.search,'[email protected]');mkdirSync(dropdir);const drop=join(dropdir,'pm.conf');writeFileSync(drop,'[Service]\nExecStart=elsewhere\n');
 s.fake(`case "$*" in *list-units*) echo '[email protected] loaded inactive dead fixture';; *)exit 99;; esac\n`);
 const refused=s.run('bus-service.sh',['install',...args,'--dir',units,'--no-reload']);assert.notEqual(refused.status,0);assert.ok(refused.stderr.includes(drop));assert.ok(!existsSync(units));
 writeFileSync(drop,'[Service]\nEnvironment=SAFE=1\n');assert.equal(s.run('bus-service.sh',['install',...args,'--dir',units,'--no-reload']).status,0);
});


test('missing package manifest refuses before npm; npm failure removes the unpublished temp copy', t=>{
 const s=setup(t);git(s.repo,'rm','package.json');git(s.repo,'commit','-qm','missing package');const id=git(s.repo,'rev-parse','HEAD');git(s.repo,'update-ref','refs/remotes/origin/refactor',id);
 const npm=join(s.bin,'npm'),called=join(s.root,'npm-called');writeFileSync(npm,`#!/bin/bash\necho called > '${called}'\nexit 1\n`);chmodSync(npm,0o755);
 const r=s.run('stack-copy.sh',['copy',id,'--copies',s.copies]);assert.notEqual(r.status,0);assert.match(r.stderr,/package.json/);assert.ok(!existsSync(called));assert.ok(!existsSync(join(s.copies,id)));
 git(s.repo,'reset','--hard',s.id);git(s.repo,'update-ref','refs/remotes/origin/refactor',s.id);
 const tar=join(s.bin,'tar');writeFileSync(tar,'#!/bin/sh\n/usr/bin/tar \"$@\" || exit $?\nfor a; do dest=\"$a\"; done\nrm \"$dest/package.json\"\n');chmodSync(tar,0o755);
 const absent=s.run('stack-copy.sh',['copy',s.id,'--copies',s.copies]);assert.notEqual(absent.status,0);assert.match(absent.stderr,/package.json.*missing/);assert.ok(!existsSync(called));unlinkSync(tar);
 const fail=s.run('stack-copy.sh',['copy',s.id,'--copies',s.copies]);assert.notEqual(fail.status,0);assert.match(fail.stderr,/npm ci failed/);assert.ok(existsSync(called));assert.deepEqual(execFileSync('ls',['-A',s.copies],{encoding:'utf8'}),'');
});


async function until(fn,ms=10000){const end=Date.now()+ms;while(Date.now()<end){if(fn())return;await new Promise(r=>setTimeout(r,25));}throw Error('fixture startup timed out');}
async function childResult(command,args,env,input){
 const p=spawn(command,args,{env,stdio:['pipe','pipe','pipe']});let stdout='',stderr='';
 p.stdout.on('data',c=>stdout+=c);p.stderr.on('data',c=>stderr+=c);p.stdin.end(input);
 const timer=setTimeout(()=>p.kill('SIGKILL'),15000);
 try{const [status]=await once(p,'close');return {status,stdout,stderr};}finally{clearTimeout(timer)}
}
test('real pinned install loads bus and Console; same-copy mosaic talk passes proof, other trees refuse', {timeout:180000},async t=>{
 const s=setup(t,true);
 const copied=s.run('stack-copy.sh',['copy',s.id,'--copies',s.copies]);assert.equal(copied.status,0,copied.stderr);
 const root=join(s.copies,s.id),url=f=>pathToFileURL(join(root,f)).href;
 const {checkEnginePin}=await import(url('packages/conversation/src/pi-pin.mjs'));assert.equal(checkEnginePin(root).version,'0.85.1');
 const f=fixture(join(s.root,'home'));notifyConfig(f.dataRoot,'acme',null);
 // Only synthetic configuration, no inherited credentials/agent environment.
 const env={...s.env,MOSAIC_CONFIG:f.config};
 const host=spawn(join(root,'scripts/mosaic'),['bus','start','acme'],{env,stdio:['ignore','pipe','pipe']});let hostOut='',hostErr='';
 host.stdout.on('data',c=>hostOut+=c);host.stderr.on('data',c=>hostErr+=c);
 try{await until(()=>hostOut.includes('bus host up')||host.exitCode!==null);assert.match(hostOut,/bus host up/,hostErr);}
 finally{if(host.exitCode===null&&host.signalCode===null){const done=once(host,'close');host.kill('SIGTERM');await done;}}
 const web=spawn(process.execPath,[join(root,'packages/webui/src/cli.mjs'),'serve','--port','0','--business','acme','--board','http://127.0.0.1:9'],{env,stdio:['ignore','pipe','pipe']});let webOut='',webErr='';
 web.stdout.on('data',c=>webOut+=c);web.stderr.on('data',c=>webErr+=c);
 try{await until(()=>/Mosaic Console: http:/.test(webOut)||web.exitCode!==null);const port=webOut.match(/127\.0\.0\.1:(\d+)/)?.[1];assert.ok(port,webErr);assert.equal((await fetch(`http://127.0.0.1:${port}/healthz`)).status,200);}
 finally{if(web.exitCode===null&&web.signalCode===null){const done=once(web,'close');web.kill();await done;}}
 // The production runtime derives cliPath. Only agent ancestry is mocked;
 // readProcess passes through for tester.mjs (row 110).
 // real pid/start/argv/nonce and the runtime's entry-path binding remain intact.
 const proofScript=join(s.root,'proof-runtime.mjs');
 writeFileSync(proofScript,`
 import {mock} from 'node:test';
 const humanURL=${JSON.stringify(url('packages/bus/src/human.mjs'))};
 const real=await import(humanURL);
 mock.module(humanURL,{namedExports:{readProcess:real.readProcess,verifyHuman:(proof,options)=>real.verifyHuman(proof,{...options,readProcess:pid=>({...real.readProcess(pid),ppid:1})})}});
 const {startBroker}=await import(${JSON.stringify(url('packages/bus/src/runtime.mjs'))});
 const runtime=await startBroker({dataRoot:${JSON.stringify(f.dataRoot)},businesses:${JSON.stringify(BUSINESSES)}});
 const broker=runtime.broker;
 const pm=broker.bindLaunch({business:'demo',role:'pm',run:'pm-fixture',harness:'pi'});broker.request(pm,{verb:'role.claim'});
 const request=broker.request.bind(broker);broker.request=(cap,r)=>{const result=request(cap,r);if(r.verb==='message.send'&&r.args.to==='pm')request(pm,{verb:'message.send',args:{to:'human',body:'same-copy reply',in_reply_to:result.id}});return result;};
 process.on('SIGTERM',async()=>{await runtime.close();process.exit(0)});
 console.log('proof runtime ready');
 `);
 const proof=spawn(process.execPath,['--experimental-test-module-mocks',proofScript],{env,stdio:['ignore','pipe','pipe']});let proofOut='',proofErr='';
 proof.stdout.on('data',c=>proofOut+=c);proof.stderr.on('data',c=>proofErr+=c);
 const socket=join(f.dataRoot,'bus','broker.sock');
 try{
  await until(()=>proofOut.includes('proof runtime ready')||proof.exitCode!==null);assert.match(proofOut,/proof runtime ready/,proofErr);
  const result=await childResult(join(root,'scripts/mosaic'),['talk','pm','hello','--business','demo','--wait','1'],env);
  assert.equal(result.status,0,result.stderr);assert.match(result.stdout,/sent .* to pm/);assert.match(result.stdout,/same-copy reply/);
  for(const other of [ROOT,join(s.root,'other-copy')]){
   if(other!==ROOT)cpSync(join(root,'packages'),join(other,'packages'),{recursive:true});
   const result=await childResult(process.execPath,[join(other,'packages/bus/src/human-cli.mjs'),socket],env,JSON.stringify({business:'demo',verb:'inbox'})+'\n');
   assert.notEqual(result.status,0);assert.equal(result.stderr.trim(),'human-required');
  }
 }finally{if(proof.exitCode===null&&proof.signalCode===null){const done=once(proof,'close');proof.kill('SIGTERM');await done;}}
});


test('bus status reads effective copy/pm/drop-ins without writes; check refuses an overridden ExecStart',t=>{
 const s=setup(t);assert.equal(s.run('stack-copy.sh',['copy',s.id,'--copies',s.copies]).status,0);
 const copy=join(s.copies,s.id),drop=join(s.root,'pm.conf');
 const rows=`LoadState=loaded\nWorkingDirectory=${copy}\nExecStart={ path=${copy}/scripts/mosaic ; argv[]=${copy}/scripts/mosaic bus start demo --pm ; }\nDropInPaths=${drop}\n`;
 s.fake(`case "$*" in *show*) cat <<'ROWS'\n${rows}ROWS\n;; *is-active*) echo inactive;; *is-enabled*) echo disabled;; *)exit 99;;esac\n`);
 const status=s.run('bus-service.sh',['status','demo']);assert.equal(status.status,0,status.stderr);assert.match(status.stdout,new RegExp(`copy: ${s.id}`));assert.match(status.stdout,/pm: on/);assert.ok(status.stdout.includes(drop));
});


test('drop-ins in either override field and malformed metadata refuse; uninstall also checks --no-reload',t=>{
 const s=setup(t),units=join(s.root,'units'),dropdir=join(s.search,'[email protected]');mkdirSync(dropdir);const drop=join(dropdir,'override.conf');
 for(const field of ['ExecStart','WorkingDirectory']){
  writeFileSync(drop,`[Service]\n${field}=override\n`);
  s.fake(`case "$*" in *list-units*) echo '[email protected] loaded inactive dead fixture';; *)exit 99;;esac\n`);
  const r=s.run('bus-service.sh',['install','--dir',units,'--no-reload']);assert.notEqual(r.status,0);assert.ok(r.stderr.includes(drop));assert.ok(!existsSync(units));
 }
 s.fake('exit 0\n');s.analyze('exit 0\n');const unknown=s.run('bus-service.sh',['install','--dir',units,'--no-reload']);assert.notEqual(unknown.status,0);assert.match(unknown.stderr,/unknown/);
 mkdirSync(units);const file=join(units,'[email protected]');writeFileSync(file,'unchanged');
 s.fake("echo '[email protected] loaded active running fixture'\n");assert.notEqual(s.run('bus-service.sh',['uninstall','--dir',units,'--no-reload']).status,0);assert.equal(readFileSync(file,'utf8'),'unchanged');
});


test('install never shows a template name on systemd 261; template drop-ins still refuse',t=>{
 const s=setup(t),units=join(s.root,'units'),calls=join(s.root,'systemctl-calls');
 s.fake(`echo "$*" >> '${calls}'\ncase "$*" in *show*[email protected]*) echo 'neither a valid invocation ID nor unit name' >&2; exit 1;; *list-units*) echo '[email protected] loaded inactive dead fixture';; *)exit 99;; esac\n`);
 const result=s.run('bus-service.sh',['install','--dir',units,'--no-reload']);assert.equal(result.status,0,result.stderr);
 assert.doesNotMatch(readFileSync(calls,'utf8'),/show mosaic-bus@\.service/);
 // This rejection arm is deliberately exercised; it is not a dead show reply.
 assert.equal(spawnSync(join(s.bin,'systemctl'),['--user','show','[email protected]'],{env:s.env}).status,1);
 const dropdir=join(s.search,'[email protected]');mkdirSync(dropdir);const file=join(dropdir,'pm.conf');writeFileSync(file,'[Service]\nExecStart=override\n');
 const before=readFileSync(join(units,'[email protected]'),'utf8');
 const denied=s.run('bus-service.sh',['install','--dir',units,'--no-reload']);assert.notEqual(denied.status,0);assert.ok(denied.stderr.includes(file));assert.equal(readFileSync(join(units,'[email protected]'),'utf8'),before);
});
test('unlisted instance drop-in is found in another unit lookup directory; path discovery errors refuse',t=>{
 const s=setup(t),units=join(s.root,'units'),second=join(s.root,'second-search');mkdirSync(second);
 const dropdir=join(second,'[email protected]');mkdirSync(dropdir);const file=join(dropdir,'cwd.conf');writeFileSync(file,'[Service]\nWorkingDirectory=/other\n');
 s.analyze(`printf '%s\\n' '${s.search}' '${second}'\n`);
 s.fake("case \"$*\" in *list-units*) echo '[email protected] loaded inactive dead fixture';; *)exit 99;; esac\n");
 const denied=s.run('bus-service.sh',['install','--dir',units,'--no-reload']);assert.notEqual(denied.status,0);assert.ok(denied.stderr.includes(file));assert.ok(!existsSync(units));
 s.analyze('exit 1\n');const failed=s.run('bus-service.sh',['install','--dir',units,'--no-reload']);assert.notEqual(failed.status,0);assert.match(failed.stderr,/unit-paths failed/);assert.ok(!existsSync(units));
});

// Row 108: inherited drop-ins apply even without a loaded bus instance.
for(const name of ['mosaic-.service.d','service.d'])test(`inherited ${name} override refuses without changing the unit`,t=>{
 const s=setup(t),units=join(s.root,'units');mkdirSync(units);
 const target=join(units,'[email protected]');writeFileSync(target,'previous unit bytes');
 s.fake('exit 0\n');
 const dropdir=join(s.search,name);mkdirSync(dropdir);const file=join(dropdir,'override.conf');
 for(const field of ['WorkingDirectory','ExecStart']){
  writeFileSync(file,`[Service]\n${field}=/other\n`);
  const denied=s.run('bus-service.sh',['install','--dir',units,'--no-reload']);
  assert.equal(denied.status,1,denied.stderr);assert.ok(denied.stderr.includes(file));assert.equal(readFileSync(target,'utf8'),'previous unit bytes');
 }
 writeFileSync(file,'[Service]\nEnvironment=SAFE=1\n');
 const allowed=s.run('bus-service.sh',['install','--dir',units,'--no-reload']);assert.equal(allowed.status,0,allowed.stderr);
});
test('inherited drop-in unreadable directory or file refuses before writing',t=>{
 const s=setup(t),units=join(s.root,'units');mkdirSync(units);const target=join(units,'[email protected]');writeFileSync(target,'previous unit bytes');s.fake('exit 0\n');
 const dropdir=join(s.search,'service.d');symlinkSync(join(s.root,'absent-dir'),dropdir);
 const dir=s.run('bus-service.sh',['install','--dir',units,'--no-reload']);assert.equal(dir.status,1);assert.ok(dir.stderr.includes(dropdir));assert.equal(readFileSync(target,'utf8'),'previous unit bytes');
 unlinkSync(dropdir);mkdirSync(dropdir);const file=join(dropdir,'broken.conf');symlinkSync(join(s.root,'absent-file'),file);
 const broken=s.run('bus-service.sh',['install','--dir',units,'--no-reload']);assert.equal(broken.status,1);assert.ok(broken.stderr.includes(file));assert.equal(readFileSync(target,'utf8'),'previous unit bytes');
});