On GitHub issue page, there doesn't seem to be a place to show that I also share this problem (e.g. upvote, +1) to let the developers prioritize this issue.
Is there a way to do this? If know, how do developers know which issues affect most people?
Update 2016-03-11: What do you know, GitHub have just added a feature to add reactions to issues (and PRs and comments). Among the reactions available is a +1. This will probably be the way to go.
As of writing, this is not possible. There's a feature request dating back to 2013 for this.
There's even an open letter listing this issue.
Instead, the standard procedure is to reply "+1" to the issue, which puts you on the list of issue participants. The downside is that this introduces a lot of spam - to the issue itself and to anyone subscribed to the issue.
If your project is also on Github, create an issue on your project detailing your relationship to that dependency. Link to the dependency's issue that you're blocked on.
Github recognises such inter-issue links and acknowledges them inline with comments on the dependency's issue in question.
Example from ariya/phantomjs#10196, which many other projects are blocked on:
This gives more context than a “+1” and the tags on the Closed/Open/Merged tags on the right are easy to scan when reading the issue comments.
As a maintainer, I have to disagree with the answers telling you to give a ":+1:" on the issue. We use that as a signal that the maintainers have "blessed" a feature, i.e, we're likely to accept a pull request that implements/fixes the issue. As was pointed out, a bunch of thumbs ups raises the noise level and makes it difficult to find relevant info when you try to work on the it.
I also disagree with creating a duplicate issue. There are always many more things to create/fix. Having duplicates in the backlog makes it difficult to determine what needs worked on. Imagine if dozens of people creating a new issue for the same problem.
The one exception to this is if you have a separate GitHub project that depends on my project. In that case, create an issue on your repository with a link to the issue on my repository. The benefits are two fold.
That's great, but you've not answered my question. How do I indicate that I'm having the same problem.
Well, it depends. If there's only one or two other people reporting it already, or if the issue is quite old, add a comment containing a detailed bug report on the existing issue. This gives me a "wake up call" and alerts me to the fact that this problem still exists. It's very easy to lose track of a particular bug/feature request. I'd appreciate the reminder.
If the issue already has a number of people reporting it, and was recently active, I'd just not do anything. At least, not unless you have something to add to the conversation. Do you have a solid way to reproduce it? Do you have an idea about what line of the code needs fixed & how? Do you have a differing view point on how it should be fixed, or do you agree with proposed plans to fix it?
These are the things I want to know as a maintainer. I don't need or want a bunch of "Me too"s. What I need is people who are involved in helping us fix it by discussing it and making it dirt simple to reproduce.
This feature is missing. But you can always simply open the issue and write a comment. In my opinion it's better to just write +1 than doing nothing. Think twice whether it's useful to let the maintainer know you also have the issue or are interested in a feature request or not.
In most cases it might be useful to provide some additional information about your environment or the specific conditions where you run into the problem.
Never open a duplicate of the issue.