Is this person sabotaging my chances at getting a job?

Let me be blunt, as someone with a couple of decades in the trenches: for most fresh ink job candidates, the endorsement letter from the adviser, which is effusive in its detailed elaboration of the importance of your developing research and indeed always does contain some criticism as a basis for the credibility of its enthusiasm, is *the single most important part* of your job application in the fields I know well, which straddle humanities and social sciences. The most important thing an adviser ever does for a PhD student is craft that letter and keep it updated, sometimes for years to come. The obligation is fucking solemn. It's what it means to "advise" someone to the PhD. A lot of younger graduate students don't understand this, so it's worth emphasizing for the future utility of this question. If your adviser is not going to write that kind of letter for you, but otherwise you cannot detach from him/her, for whatever reason (might be the greatest substantive mentor in every other way, might be the only option, whatever), you need to cultivate a close and sympathetic relationship with another faculty member who is likely to serve on your dissertation committee who can serve as an informal substitute for that role in the future. The way the academic world works, you can't hardly get in the door without an introduction from someone others are going to trust to endorse you truthfully and in detail. It's why people cultivate connected and powerful advisers, correctly so; but sometimes they can be connected and powerful to a fault, too busy to really focus on one student at a time, presumptive about the significance of their mere affirmative endorsement (I've seen 5 sentence reference letters in job searches, which are just guaranteed to harm the candidate by sending the message that their adviser did not give enough of a shit to write a real letter). The best often hit 3 or more pages, single spaced, like a mini tenure letter. If you don't have someone to write that letter for you -- someone who will be recognized as a trustworthy judge of talent both laterally and longitudinally in the field and whose reputation commands some level of respect -- you are at a disadvantage, possibly a severe one, in the job search process. Even if you are sure you will have such a relationship with your adviser, it is always advisable to cultivate a backup person who you feel confident would step into the role. Advisers do change jobs, lose their marbles, get too big for their britches, or turn out to be different than you thought. For the OP, this is why you must work this out with the adviser personally. I would not myself recommend having a meeting that includes the DGS (speaking as someone with many years of DGSing under my belt too). Here's the thing: it is in the adviser's interest for you to be placed, and placed well. Any rational adviser gives this matter full and unbiased attention. There are legitimate reasons and adviser may guide you towards or away from particular jobs, and that's a conversation to have in advance of applying. On the one hand, for example, he could really think you are selling yourself (and thus him) short by angling for a temporary position, let's say; on the other, he could have more than one student in a given search and be signaling a ranking of those candidates to his colleagues on the search committee in question. There is no advantage to you whatsoever to treating this as (or allowing it to develop into) an adversarial situation. The advice treating it like that is already the case, I feel, is idealistic. Your options are to communicate more effectively with your adviser or find a backup person to serve the same function with respect to your references, and let them know you need the adviser-grade letter from them.

The problem is that a good reference from him would be extremely valuable. No, the problem is that he's always going to find a reason not to give you a good reference. Take him off your applications but keep hitting him up about opportunities so you can maybe still get one from him if he changes his mind.

My advisor also said that he would give me a glowing reference if he felt the job was right for me. This seems to suggest that he is giving purposefully bad information to your potential employers. Regardless of the reason, that's a shockingly terrible thing to do.

Wow. OK, this is a big problem, since if you *don't* have a letter from your adviser, it will color the rest of your application in most searches, unless the adviser him/herself is widely disliked, perhaps (and then there will be negative bias against her/his students anyway). So you gotta get this sorted out. Apparently, your adviser thinks you should be vetting your options through him first? I always appreciate knowing where my students are applying before I get the prompt for the reference letter, but I would rarely veto an application as a bad fit a priori (and then I would at most suggest my criticism, and certainly not let it enter my letter of reference in any way if I still agreed to write for it!). Maybe you can have your adviser upload a generic letter to Interfolio that you can use for lower-tier searches, save the custom-tailored letter for the jobs he approves of you pursuing?

Yes, he is trying to control this and it's completely inappropriate. Remove him

you want someone in University admin who can confirm the barest details of your research. No, you really really don't, unless your discipline is extremely corporatized somehow. I mean, maybe it's possible that these are b-school postdocs or something, but that seems really REALLY unlikely. In an academic search, an application packet without a letter from the adviser is at a significant disadvantage unless your adviser is widely known to be pretty crazy and/or an asshole. Letters of recommendation in academic job searches are obviously skewed towards the positive but are also, really, quite frank. A letter that just confirmed the barest details of your research, instead of enthusiastically explaining it to the reader and describing its likely outlets while also noting and explaining any obvious flaws in your vita, would be a deeply harmful letter to have in your packet. In your shoes, I would try to arrange a minimally-confrontational meeting between you, your adviser, and your DGS.

Your advisor is being very proprietary about you and your career and in that sense I feel he's' being hugely out of line. I'm glad he's proud of you, but it's not his decision what job you take or who you'd work for. You need experience at these jobs and that he's sabotaging the reference process is not okay. If I had a lot of mutual trust with him I would try to discuss it with him. If I didn't think I would trust him to take that kind of feedback well I'd probably try to get a reference from one of my co-graduate students instead of including my advisor on future applications.

Those commenting that don't live in academia aren't being helpful here. What's your relationship with your advisor like outside of this? What has gone down with other advisees in their job hunts? My (awesome) advisor was similar in that he was less supportive of jobs that were not a good fit. And based on other people I've seen, this is pretty normal. I think that a face to face meeting where you are honest about your goals is important. He may be working off an entirely different set of assumptions. Also remember that he knows the market better than you do. Scenario: Bob, I wanted to chat about job search. I greatly appreciate all that you've done. I just want to make sure we're on the same page. To be honest, I have a strong goal right now of finishing. Even if this means taking (subpar) postdoc, I need to start earning income. I realize that (subpar) postdoc has drawbacks X, Y, and Z, but I am okay with that because my ultimate goal is A. And I'm under the impression that I don't need to have a prestigious postdoc to get to A, like I would if I wanted to get to B. He is likely working off the assumption that you want the most prestigious R1 TT position and is trying to get you there. Just a guess...

It sounds like your advisor may mean well, but he is clueless, meddling, and completely out of line. It's not his job to figure out whether a job is right for you, it's your job to do that. A person who agrees to be a reference should just candidly answer any questions a prospective employer has... and that's it. It sounds like you should find a different reference to give.